For a moment, it appeared as if Bayern Munich could actually be on its way out of the Champions League in the quarterfinal stage. Patrice Evra's goal had Manchester United shockingly ahead of the reigning European and German champions. But an immediate answer by Pep Guardiola's side kept Bayern's hope at a Champions League repeat alive and well, as Bayern eliminated David Moyes' Manchester United on a 4-2 aggregate after a 3-1 triumph.
Guardiola's former team, Barcelona, was not as fortunate, as Atletico Madrid's furious pressure at the beginning and sound defending throughout stifled its Spanish rival. Lionel Messi and Neymar were held at bay, and Koke's goal held up as Diego Simeone's side -- without the injured Diego Costa -- advanced with a 1-0 victory (2-1 aggregate). As a result, the Champions League semifinals include Bayern, Atletico, Real Madrid and Chelsea.
Here is what caught our eye from Wednesday's second legs:
Player of the Day: Diego Godin, Atletico Madrid
With six minutes to go, Godin, charging forward, was fouled by Marc Bartra just inside his own half. It didn't seem appropriate to ask just what the Uruguayan center back thought he was doing there, leading a break rather than protecting his own goal, but it did seem to sum up Atletico's attitude. Although it was nervous towards the end, far more nervous than it should have been given how many chances Atletico wasted in the first half, it never felt like it was under siege.
There were plenty of fine performances from Atletico players - Koke, Juanfran, Tiago, Gabi and Raul Garcia were all superb, and in the day's other game Arjen Robben, Franck Ribery, Antonio Valencia and Chris Smalling all had fine nights - but it was Godin, the image of controlled defiance, whose performance summed up the night.
Moment of the Day: Patrice Evra's goal and Mario Mandzukic's immediate response
Manchester United's moment of hope lasted all of 73 seconds. First Patrice Evra blasted Manchester United into the lead with a sensational first-time strike from outside the box, a genuinely brilliant goal and one that came without warning. For 50 seconds United celebrated and dared to think the impossible.
Then Bayern kicked off again and five passes later, Ribery crossed, Evra let Mario Mandzukic steal in front of him and the Croatian headed an equalizer, a sign of Bayern's resilience as much as its ability.
From then on the momentum was with the European champions. Although Wayne Rooney hesitated fatefully in front of goal for the second time of the evening with the score at 1-1, it felt as though United's only hope was to cling on for penalties. That disappeared once Thomas Muller had turned to squeeze in Robben's low cross, and when Robben added a third after a familiar diagonal scamper, the game was won.
Major Takeaway of the Day
There were times when Bayern Munch seemed to be playing with a back two, with Philipp Lahm and David Alaba pushed high and narrow, flanking Toni Kroos at the back of midfield to leave just Dante and Jerome Boateng at the back. Guardiola has shown before, both at Barcelona and at Bayern, that against sides he expects will back men behind the ball he is quite happy to shift his players into unorthodox positions high up the pitch.
The drawback can be a decrease in verticality; that the more players there are high up the pitch the fewer players there are to break at pace from deep to add thrust. Barcelona also seemed to play with fewer than the expected number of defenders, although that was less by design than as a consequence of their extraordinary discomfort under the high ball. Again and again in the first half Atletico troubled them with direct play and crosses.
The lesson was clear, both by comparison with Guardiola's time and Guardiola's Bayern: You can get away with reducing the number of defenders only if the rest of the side is good enough, both in terms of possession and position, to allow it.
Assessing The Final Four
Atletico is dogged and tough, the bristling, pragmatic embodiment of its manager, Simeone. It is supremely compact, happy to defend deep or to press, a superbly drilled tactical unit. It also has in Diego Costa arguably the in-form forward in Europe at the moment - although he missed out through injury against Barcelona. The question all season has been whether its relatively small squad can sustain its intense style all season.
Bayern, the reigning European champion, is magnificent in possession and has in Guardiola a coach who seems to see the game on another level to his rivals, forever micromanaging, making changes to exploit weaknesses or protect flaws nobody else has even noticed. His critics say he over-complicates things and that the high line he prefers leaves Bayern susceptible to pace, but if only two defeats in all competitions all season - both in dead rubbers - is the sort of vulnerability most teams dream of.
Chelsea is short of a striker and with Nemanja Matic cup-tied can lack drive in midfield, but in Jose Mourinho it has the best manager in the world at one-off games. John Terry revealed on Tuesday that Mourinho had prepared his side for a variety of different scenarios against PSG: 1-0, 2-1, 3-1. It's hard to imagine any other coach being so meticulous. Whether Chelsea has the best defense left in the competition is arguable, but it is certainly the team best equipped to sit deep and spring forward with rapid counter-attacks.
Real Madrid has awesome forward power: Cristiano Ronaldo and Gareth Bale and technically gifted, quick, powerful and direct on the flanks, and Karim Benzema has found a way of offering a focal point without obstructing either. The problem is at the back, where weaknesses were shown up both in the Clasico and by Borussia Dortmund. It is vulnerable to pace, particularly when attacked in wide areas.