Neither team showed much intent in an awful first half, the most notable incidents of which were an André Gomes injury, leading to his replacement by Enzo Perez, and a couple of missed chances as André Almeida and Gonzalo Castro fired long shots wide of goal. Andre Schurrle being withdrawn at half-time summed up the extent to which it felt both sides wanted to win the game, and it seemed we were in for another dour 45 minutes of football.
In the 60th minute, however, the game exploded into life. The best chance of the game fell to Hajime Hosogai, a corner going uncleared and falling at his feet close to goal, but he couldn't get his shot away and Ezequiel Garay was able to get the block in. Leverkusen would soon be ruing the miss, because Benfica immediately went on the attack, Andre Almeida's run and cutback finding Cardozo in the area, and the big Paraguayan took one touch to leave Kadlec in a heap before clipping a wonderfully cool finish over Bernd Leno.
Leverkusen soon had a chance to equalise from Lars Bender's fine cross into the area which eluded Artur Moraes, but Almeida was there to take the ball off Gonzalo Castro before Moraes made a fine save from the follow-up. Jens Hegeler then had another chance to equalise after bursting down the left channel with a good run, but Artur was equal to his effort.
There were suddenly chances at both ends, and Ola John almost added a spectacular second for Benfica when he broke down the left wing, but instead of attempting a shot from a tight angle, tried a chip into the far corner, but he was inches away from successfully executing the finish with Leno well beaten.
Leverkusen attempted to turn the screw and force an equaliser, but disciplined defending from Benfica, with Luisao giving a typically mature performance to keep the hosts out. Leverkusen did have a late chance to equalise when Sidney Sam had a good opportunity to score a free-kick from the edge of the box, but his effort crashed into the wall, and Bayer were fortunate to see Lima's wayward pass fail to find Eduardo Salvio, who had run clear, on the counter.
In the end, Benfica held on for a creditable away victory and one that will give them a huge bonus for the second leg. A particularly impressive one given the big names left on the bench, and the Portuguese side will have hopes of going all the way now.