In the Catalan corner, the scorer of 52 goals this season, the reigning World Player of the Year and the man some suggest ranks alongside Pele and Diego Maradona as the greatest ever. And his Manchester United counterpart? That would be Darron Gibson. The Champions League finalists took comparisons to an improbable extreme. The outstanding player in the second leg of one semi-final was Lionel Messi; the pivotal figure in the other, a man the majority believe unworthy of the shirt. Lionel is lionised globally, 'Gibbo' was hounded off Twitter by his own supporters. After the sublime came a ridiculous outcome.
As the resident scapegoat effected a strange, and surely temporary, transformation into the star, it was emblematic of an odd occasion at Old Trafford. Anderson, having scored twice in 127 United games, managed another two in the space of five minutes. John O'Shea wore the captain's armband; this, it seemed necessary to remind ourselves, was a Champions League semi-final.
In recent years, they have featured a Paul Scholes wonder-goal against Barcelona and a Kaka masterclass when AC Milan visited, but here the sense of wonder was generated first by the teamsheet and then by the excellence of the understudies. Perhaps the watching Pep Guardiola will formulate a plan to halt Gibson; perhaps he left Old Trafford having learned little other than not to underestimate whichever 11 United field.
If the initial temptation was to suggest Sir Alex Ferguson had devalued the competition, the eventual conclusion was that he had made an accurate assessment of Schalke's abilities. This was the sort of routine win that was reminiscent of the trips of Premier League strugglers to Old Trafford, except that United began with a two-goal headstart.
After the Spanish Civil War, the Anglo-German encounter was more even-tempered, but certainly not even: it is rare that this stage of the competition witnesses such as mismatch. United's elite were spared for Chelsea, their understudies rolled out for a game that, in theory, is one of the biggest in the footballing calendar.
"I think we had to trust them sometimes," Ferguson said. "I didn't sleep last night thinking about it - I woke up four times - but they did me proud. When I analysed each individual, they were Manchester United players so why couldn't I play them? I'm glad I was vindicated."
He certainly was. An unexpectedly perceptive pass from Gibson released the excellent Antonio Valencia who put United ahead with expertise. Seven minutes later, Gibson's low shot was spilled by Manuel Neuer and trickled over the line. Likened to Peter Schmeichel in the first leg, this was the Schalke goalkeeper's Massimo Taibi moment.
More characteristic of the giant German were terrific stops to deny Anderson and Michael Owen. In between, however, Anderson revealed a hitherto hidden predatory instinct to convert twice after low, right-wing crosses from Nani and Dimitar Berbatov. They were a reward for his exuberance; the Brazilian buzzing around with typical enthusiasm.
He, unlike some of this side, may face Barcelona. "We're playing a fantastic team but I don't think we should be going there lacking in confidence," Ferguson added. "This team can win the cup. We've got a great team full of ability."
The men his side vanquished concurred. "Congratulations to Manchester United on qualifying for the final," said Schalke's manager, Ralf Rangnick. "It was a deserved victory in both games; they were the better team."
Jose Manuel Jurado had pulled a goal back with a shot that flew past Edwin van der Sar but, apart from Neuer's first-leg saves, it was a rare highlight for the visitors. The outcome seemed to say as much about them as it revealed about United: Barcelona are as intimidating as Schalke proved unthreatening.
The Bundesliga's 10th-best side and perhaps the world's finest have little in common, save a place on United's fixture list. But, as a trip to Wembley for a second European summit meeting was ensured, 43 years after the first, it was fitting that a celebratory occasion had more than a hint of nostalgia.
The United supporters went through their repertoire of choruses saluting past heroes, the Stretford End and the East Stand trading tributes for Eric Cantona and Bryan Robson. Neither won a European Cup or Champions League semi-final, meaning the perceived liability, Gibson, has accomplished something the legends didn't. To paraphrase a hackneyed chant: Champions League semi-final, you're having a laugh.
MAN OF THE MATCH: Darron Gibson - No, really.
MANCHESTER UNITED VERDICT: Ferguson's gamble paid off as the majority of the team who are set to face Chelsea were given a game off. Of those who did play, however, Valencia enhanced his claim to be deemed as the first-choice right winger, even though Nani may be United's player of the year. Anderson's energy means he ought to play against both Chelsea and Barcelona, while Darren Fletcher's return as a substitute was another bonus for United.
SCHALKE VERDICT: Their performance over two legs against United makes their 5-2 win against Inter Milan in the San Siro still more of a mystery. When Neuer leaves in the summer, Rangnick will have a huge job to create a competitive team without a world-class goalkeeper.