It was the battle of the breasts as Katy Perry and Kate Hudson had a boob-off at last night's amfAR Inspiration Gala.
Both were flaunting their assets as they posed together during the event which raises money for the Foundation's AIDS research programmes.
Kate took the plunge in a daring red dress, while Katy (whose real surname is also Hudson, fact fans) put on more than a show as she took to the stage to perform at the event.
But Katy's charitable turn didn't end at treating guests with the sight of her famous cleavage, as the singer is set to donate one of her guitars to help raise money for the organisation.
A spokesperson for the charity said: "We're thrilled to announce that superstar Katy Perry has donated a guitar to auction off at amfAR's Inspiration Gala Los Angeles tomorrow. Katy will personalise an autograph on the guitar to the lucky winner. All proceeds benefit our research programs... Thank you, Katy!"
amfAR's Inspiration Gala Los Angeles
amfAR's Inspiration Gala Los Angeles - Inside(01 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Katy Perry performs onstage at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(02 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Katy Perry performs onstage at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(03 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Katy Perry performs onstage at Grey Goose hosted amfAR Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(04 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Kate Hudson attends amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Red Carpet(05 of45)
LOS ANGELES, CA - OCTOBER 11: Model Alessandra Ambrosio arrives at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(06 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Katy Perry attends amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Red Carpet(07 of45)
LOS ANGELES, CA - OCTOBER 11: Model Alessandra Ambrosio arrives at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Red Carpet(08 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Beth Behrs and Designer/amFAR Chairman Kenneth Cole arrive at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Red Carpet(09 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Jennifer Coolidge and TV personality George Kotsiopoulos arrive at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(10 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Kate Hudson attends amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(11 of45)
LOS ANGELES, CA - OCTOBER 11: Model Alessandra Ambrosio attends amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(12 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Chelsea Handler speaks onstage during amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(13 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Chelsea Handler speaks onstage during amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(14 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Lance Bass, actress Rumer Willis and guest attend amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(15 of45)
LOS ANGELES, CA - OCTOBER 11: (L-R) Gala Producer Josh Wood, Designer/amFAR Chairman Kenneth Cole, and Actress Kristin Davis attend amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(16 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Sarah Jessica Parker speaks onstage at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(17 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Sarah Jessica Parker speaks onstage at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(18 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Sarah Jessica Parker onstage at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(19 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Kristin Davis speaks onstage amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(20 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Kate Hudson and singer Katy Perry attend amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(21 of45)
LOS ANGELES, CA - OCTOBER 11: Actresses Sarah Jessica Parker and Chelsea Handler attend amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(22 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Kate Hudson and singer Katy Perry attend amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(23 of45)
LOS ANGELES, CA - OCTOBER 11: Model Alessandra Ambrosio and Jamie Mazur attend amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(24 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Katy Perry performs onstage at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(25 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Katy Perry performs onstage at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(26 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Katy Perry performs onstage at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(27 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Katy Perry performs onstage at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(28 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Katy Perry performs onstage at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(29 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Sarah Jessica Parker (L) and Comedian Chelsea Handler attend amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(30 of45)
LOS ANGELES, CA - OCTOBER 11: Model Alessandra Ambrosio attends amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(31 of45)
LOS ANGELES, CA - OCTOBER 11: Model Alessandra Ambrosio attends amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(32 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Katy Perry and New York Giants Chairman/Executive VP Steve Tisch attend amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(33 of45)
LOS ANGELES, CA - OCTOBER 11: Model Alessandra Ambrosio attends amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(34 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Katy Perry performs at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(35 of45)
LOS ANGELES, CA - OCTOBER 11: Auctioneer and actress Kristin Davis speak onstage at the Grey Goose hosted amfAR Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(36 of45)
LOS ANGELES, CA - OCTOBER 11: CAA Managing Partner/amFAR Honoree Kevin Huvane speaks onstage at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(37 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Jennifer Coolidge (R) speaks onstage at the Grey Goose hosted amfAR Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(38 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Katy Perry performs at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(39 of45)
LOS ANGELES, CA - OCTOBER 11: Actress Kristin Davis (L) speaks onstage at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(40 of45)
LOS ANGELES, CA - OCTOBER 11: Singer Katy Perry performs at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(41 of45)
LOS ANGELES, CA - OCTOBER 11: (L-R) CAA Managing Partner Bryan Lourd, Actress Kate Hudson and CAA Managing Partner Kevin Huvane attend amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(42 of45)
HOLLYWOOD, CA - OCTOBER 11: General view of atmosphere at amfAR's Inspiration Gala Los Angeles at Milk Studios on October 11, 2012 in Hollywood, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(43 of45)
LOS ANGELES, CA - OCTOBER 11: General view of atmosphere at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(44 of45)
LOS ANGELES, CA - OCTOBER 11: General view of atmosphere at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)
amfAR's Inspiration Gala Los Angeles - Inside(45 of45)
LOS ANGELES, CA - OCTOBER 11: General view of atmosphere at amfAR's Inspiration Gala at Milk Studios on October 11, 2012 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for amfAR) (credit:Getty Images)