The 31-year-old has been a lifelong fan of the group and shared an ecstatic post about the evening on Instagram.
Alongside a series of pictures and videos – which showed Adele and her pals dancing, before a selfie with Geri Horner – the Hello singer explained she last saw the band perform 21 years ago.
“Tonight with my nearest and dearest I cried, laughed, screamed, danced, reminisced and fell back in love with my 10 year old self,” she wrote. “It’s no secret how much I love them, how much they inspired me to run for my life and never look back.
“I finally got to meet Ginger, I got drunk with the girls and quite frankly I can’t believe how far I’ve come.”
After a cry-laughing emoji, Adele added: “Thank you for the madness I get to live, I couldn’t have got here without you 5 BRITISH legends! I love you!”
One of Adele’s pals also posted videos of her watching the band on his Instagram Story and the clips have since made their way over to Twitter:
The concert saw Geri apologise for walking out on the band back in 1998 – an event we are genuinely still struggling to come to terms with.
“I need to say something I should have said a long time ago,” she told the 70,000-strong audience. “I’m sorry. I’m sorry I left. I was just being a brat.
“It is so good to be back with the girls that I love.”
Saturday’s concert was the last date of the band’s current tour but Mel B sparked speculation they’ll be back, as she closed the show by shouting: “We’ll see you in February in Australia!”
Official tour dates for Down Under are yet to be officially announced.
When Geri left back in 1998, the band stayed together as a four-piece for two more years before announcing an indefinite hiatus in December 2000.
They then got back together as a five-piece for their a reunion tour which ran throughout 2007 and 2008.
The last time all five bandmembers performed together was at the London 2012 Olympics closing ceremony.