1 Guardiola has a hard act to follow in Heynckes

Now we know why Jupp Heynckes does not like to be asked about the man who will replace him at Bayern Munich this summer. Pep Guardiola will have a hard time improving this staggering side. Barcelona have been beaten before but never this comprehensively, and one shudders at the thought of how good Bayern will be once Mario Götze arrives from Borussia Dortmund for £31.5m. Heynckes will be gone by then, though. Yet against Barcelona he got his tactics spot on, as Bayern allowed the visitors the ball in harmless areas and then pounced with controlled aggression whenever they dared venture forward. The rest of Europe will surely cower at Bayern's might.

2 This is a defeat that had been coming for Barcelona

A half-fit Lionel Messi was enough to edge Barcelona past Paris-Saint Germain but not against the ultimate team. Although Barcelona might complain about two contentious goals, they will know that their aura was shredded in 90 tortuous minutes. Beyond all repair? Let us not get carried away. Yet there was a sense of decay about them at the Allianz Arena and the warning signs had been present when they were beaten by Milan and Real Madrid in February. There are too many passengers in this squad and, although there is obviously still much to admire about Barcelona, this was like watching a pallid tribute act. There is such a thing as passing for passing's sake.

3 Müller's economy of movement proves invaluable again

The absence of the injured Toni Kroos forced Bayern to move Thomas Müller inside from his role on the right. Kroos has been superb for Bayern, effortlessly dictating play, and Müller does not offer the same kind of threat; whereas Kroos is always at the heart of the action, Müller tends to operate on the fringes and perhaps that explained why none of Barcelona's defenders noticed him when he got into position to head Bayern into the lead. Müller often gives the impression that he is doing nothing but, while he is not especially quick or skilful, the 23-year-old can never be accused of hiding.

4 Barça's complacency in defence got what it deserved

Gerard Piqué might have shaved his head but, as is so often the case, there was nothing intimidating about Barcelona's defending. Last summer they wasted the opportunity to improve their defence, even though they knew that Carles Puyol's creaking knees could deprive them of their leader for long periods. Without the injured Javier Mascherano and the suspended Adriano, Tito Vilanova had to select the inexperienced Marc Bartra alongside Piqué. For a while Piqué stood firm against Bayern's aerial barrage but there was always a sense that Barcelona would crack and their defending for the first two goals was horrific.

5 Robben finally provides a flourish on the grand stage

Bayern have been haunted by their defeat by Chelsea in last season's final and no one has had to shoulder the blame more than Arjen Robben, who had a terrible penalty saved by Petr Cech in extra-time. The Dutchman has often had to settle for a place on the bench this season but the injury to Kroos has offered him a chance. Jordi Alba, who will be suspended for next week's second leg, will not be in a hurry to face him again. Robben produced an unusually mature performance and it was just a shame that his fine solo goal ought to have been disallowed for Müller's bump on Alba.