Porto stunned German champions Bayern Munich to take a 3-1 lead from the first leg of their Champions League quarterfinal at the Estádio do Dragão. The 2013 winners were caught cold by the intensity of Porto’s pressing, and within 10 minutes they found themselves two goals behind. Former Barcelona winger Ricardo Quaresma got both of them, the first from the penalty spot after Jackson Martínez was brought down by Manuel Neuer. Martínez then coolly added a third in the second half, after Thiago Alcantara had earlier reduced Bayern’s arrears.

It leaves Pep Guardiola’s side facing a massive uphill task back at the Allianz Arena next Tuesday to avoid becoming the victims of the biggest shock in this season’s Champions League. With the Bundesliga title again proving little more than a formality, a spectacular failure in Europe for the second season running -- following the 5-0 drubbing by Real Madrid a year ago -- would throw Guardiola’s whole future with the Bavarians into serious doubt.

Bayern were without several key players for this first leg, including Arjen Robben Franck Ribery and Bastian Schweinsteiger. But it was a defense missing Mehdi Benatia’s presence that was crudely exposed throughout a stirring contest in Portugal.

It was an incredible start to what was a repeat of the 1987 European Cup final, in which Porto triumphed 2-1.  With less than two minutes played, Xabi Alonso, dropping into a familiar position between Bayern’s split center-backs, took too much time on the ball on the edge of his own box and was set upon by Martínez. Having robbed the Bayern midfielder, Martínez took a touch to the side of the advancing Neuer before going down under the challenge of Germany’s No. 1.

Spanish referee Valesco Carballo was faced with determining not only whether Neuer’s slight touch to the ball was sufficient to deem it a fair challenge but, if it was a penalty, whether the change in the trajectory of the ball meant it could be seen as a clear denial of a goal-scoring opportunity. In the end Neuer was punished but escaped with just a yellow card. And he could do nothing to prevent Quaresma's confidently sending him the wrong way to put the hosts into a third minute lead.

Incredibly, Bayern’s rocky start was soon to become a disastrous one. Coach Julen Lopetegui had clearly done his homework on Bayern and had his players press Bayern’s back line in selective bursts. The plan paid off handsomely once more, giving Porto a two-goal advantage. This time it was Dante who was the man caught out and Quaresma who pounced, snatching the ball from the Brazilian and running through before coolly striking the ball low past Neuer with the outside of his right foot.

Bayern were already in a major hole and needed a response to clam the jitters and get themselves back into the tie. And, although missing so many star players, it didn’t take long for them to find one. Center-back Jérôme Boateng bombed down the right flank and delivered a bewitching low cross that somehow missed out two Porto defenders at the near post and gave Thiago the chance to stretch behind him and turn the ball past Fabiano.

Still, though Bayern predictably controlled possession, they did little with it and were unforgivably sloppy both with and without the ball. And Porto continued to pose the greater attacking threat. Before the interval, Neuer was caught out by a Sandro cross that he let slip through his grasp and was relieved to see come back off the crossbar, while Casemiro should have done better than to head a presentable chance over the Bayern goal. Neuer had to be at his best, too, to turn over a first-time shot from Mexico midfielder Hector Herrera from close range.

But in the 65th minute, Bayern’s defense fell apart once more. This time it was Boateng at fault, completely missing a header from a hopeful ball forward,  allowing Martínez to run in behind and round Neuer before stroking the ball into the net. It could prove a crucial goal, although Porto will be well aware that Bayern have ample quality to get a 2-0 win back at home that would take Guardiola’s men through.

All Goals - FC Porto 3-1 Bayern Munich - 15-04... by Video-Live