After seeing his side held to stalemates in their first two away fixtures, David Moyes was skeptical of Manchester United's trip to the BayArena to face Sami Hyypia's free-flowing Bayer Leverkusen, sitting second in the Bundesliga and unbeaten at home since March.
"The next game is always the toughest test and the most important," said the Scot at his pre-match press briefings, after United's entourage endured a "choppy landing" in Germany.
"This has become tough because Leverkusen have been on a great run of form.
"This is our last away game now and as it stands Leverkusen are in good form and in good shape in the group themselves, so we know we're going to have a game on our hands."
Robin van Persie didn't travel with the squad, owing to a groin injury, while Javier Hernandez did no favors to advocate his inclusion in the starting XI by failing to register a single attempt on goal in South Wales on Sunday. Danny Welbeck's cameo against Cardiff City wasn't impressive either, so Moyes started Shinji Kagawa as the No. 10 and Wayne Rooney just ahead of the former Borussia Dortmund man.
"I said at the start of the season that sometimes Wayne might have to play up front and Shinji in behind when Robin [van Persie] is injured."
In midfield, Ryan Giggs was paired with Phil Jones.
A team devoid any sort of creativity in midfield on Sunday looked menacing through the middle on Wednesday night.
Giggs orchestrated from his central role, dropping in between Rio Ferdinand and Jonny Evans to collect the ball and distribute play. The Welshman sprayed some lovely diagonal passes to Antonio Valencia and linked up with Kagawa equally well to inject the missing creative aid in the United set-up.
Kagawa and Giggs combined a total of 13 times throughout the game.
For the first goal, Kagawa released Giggs on the break before the latter fed Rooney out wide on the left. The England international, eventually ending the game with four assists, chipped a lovely ball on to the far post, netted home by Valencia.
United were finally able to link the two ends of the pitch. A central midfielder in Giggs took the initiative to push high up, when in possession, get into space opened up in the final third when United were out wide and play direct passes in between the lines to the attackers. With a 92% success rate.
The Welshman's magical age-defying night was summed up by his breathtaking long ball that put Luis Nani through for United's fifth late on.
Despite that Giggs is about to turn 40 on Friday, he didn't look a bit tired after covering more than ten kilometers against Leverkusen.
"You cannot question Ryan Giggs as a football player. He did not look fatigued for his age at all," Moyes said after the match.
Kagawa, on the other hand, provided United with a No. 10 who dropped deeper than Rooney usually does and help make attacking transitions with ease and effectiveness. He was aided by the continual supply of ammunition by Giggs, particularly when United broke free.
Kagawa's nimble feet and affinity for working in congested areas caused insurmountable troubles for the Bayer midfielders, who were clearly unable to contain the Japan international.
Playing in a free role, Kagawa won five fouls, with the resulting free-kick from one of them leading to Emir Spahic's own goal.
Kagawa also had crucial roles to play in United's next two goals.
In the 65th minute, Kagawa released Valencia with a sublime touch that put the Ecuadorian through. Valencia crossed into the box, only for United to win a corner that eventually led to Jonny Evans' goals.
Twelve minutes later, Kagawa chipped a wonderful ball to Rooney, who lofted it for Chris Smalling to tap-in home.
Kagawa's partnership with Rooney was not only restricted to their link-up for United's fourth.
It took the Japanese only 28 seconds to release his teammate clear on goal, albeit Rooney mistimed his run and was called back for offside.
The two combined a total of nine times, three times more than Rooney and Hernandez did against Cardiff.
"I thought Shinji played really well tonight, he was excellent, but he has been excellent when he's played off the left as well," Moyes said.
Giggs' passing vision and ability to play horizontal passes in between the lines only helped United's cause. The Red Devils still focused on attacking down the wings, with just 23% of their attacks coming down the middle of the park.
But when it did come to attacking from the centre of the field, Kagawa and Giggs ensured a smooth flow, usually missing when Rooney operates in the No. 10 slot and the likes of Cleverley and Fellaini are paired together.
The wing-play emphasis was mainly due to the high-positioning of Bayer's full-backs. It was by choice, not by force.
"Their full-backs play really high and once we got the ball we could break on them," Jonny Evans explained after the game.
While Giggs continue to defy the laws of age, something that even aroused the curiosity of the opposing Bayer centre-half, Kagawa is finally unraveling his true talents.
United now have a solid Plan B. When the wings rendered futile, Giggs and Kagawa provided options in the middle of the park on Wednesday.
A five-nil win in Germany is as good as it can get. The key is now to build up on this win when Moyes' army travels to White Hart Lane on Sunday.
All statistics are via WhoScored.com