Pep Guardiola Tears Strips off Porto in Bayern Munich's Champions League Triumph

How could we ever have doubted Pep Guardiola?

Perhaps the most telling moment of Bayern Munich’s demolition of Porto on Tuesday came midway through the second half.

Bayern were 5-0 up and cruising, all thoughts of them potentially suffering a humiliating upset forgotten.

This was a night of vindication for Guardiola and yet with the game and the tie won, he grabbed Thomas Muller by the shoulder and, with superfluous urgency in the circumstances, issued his instructions.

Matthias Schrader/Associated Press

Somehow, he had ripped his trousers during the second half so they flapped open to reveal a chunk of thigh; however the tear occurred, it seemed appropriate given his agitation, his determination to finish this in the most ruthless possible way.

After the sloppiness of the first leg, and all the defensive errors, this was a wholly professional Bayern.

Tactically, their approach wasn’t overly complicated. The narrowness of Porto’s 4-3-3 in the first leg had raised the suspicion they might be vulnerable from wide areas, and the absence of their first-choice full-backs, Danilo and Alex Sandro, only heightened that weakness.

Sure enough, the first, third and fifth goals all came from out wide: again and again, Bayern simply knocked it beyond the full-back and made hay.

The approach may not have been complicated—the way the absences of Franck Ribery and, particularly, Arjen Robben hurt Bayern in the first leg were obvious—but the way Guardiola achieved the width Bayern needed was still a surprise.

The shape was almost a 4-4-2, with Philipp Lahm operating as a right-sided midfielder. He tucked in when Bayern were out of possession, with Mario Gotze staying higher up on the left—so the shape became a lop-sided 4-3-3—but once Bayern had the ball, Lahm pulled wide and regularly isolated Bruno Martins Indi, who struggled desperately.

Michael Probst/Associated Press

Xabi Alonso and Thiago Alcantara were able to find the captain in space again and again, that route providing two of the goals.

The other key factor in Bayern’s win was the performance of Robert Lewandowski, a forward who chases, harries, presses, scores and is good in the air, while having none of the wildness of Mario Mandzukic.

His aerial presence means Bayern have the option to use crosses or to go direct from front to back in a way that Guardiola’s Barcelona perhaps lacked (not that they didn’t want to; the logic behind the Zlatan Ibrahimovic transfer was to give them a second way of playing).

Matthias Schrader/Associated Press

Lewandowski’s display was a masterclass of completeness: eight shots, three of them on target, three key passes and three aerials won, according to WhoScored.com.

Awesome as Bayern were, though, there is a sense the win told us little new.

It says much for their character and attacking excellence that they were able to overturn the effects of a disappointing first leg within 20 minutes, but then this is a side that has scored four or more on 10 occasions in the Bundesliga this season.

That the German champions can obliterate sides at home isn’t news (and, it must be acknowledged, Porto capitulated astonishingly quickly). A lack of attacking prowess was never going to stop Bayern winning the Champions League.

Michael Probst/Associated Press

What might stop them, though, is the vulnerability they showed in the first leg to pace; the sense that their defence, untested as it so often is in the Bundesliga, is just as susceptible as it proved in the semi-final against Real Madrid last season.

It’s true Bayern’s pressing was sharper on Tuesday than it was in the Dragao, with Porto often reduced to aimless punts in the vague direction of Jackson Martinez, but when the issue seems as much mental as tactical, there is no guarantee it will be equally effective in the semi-final or final.

But that’s for the future. This was a night of triumph for Guardiola as he reached a seventh Champions League semi-final out of seven.

The first leg had asked a serious question, and he devised a tactical scheme that provided a devastating answer.