Bayer Leverkusen waltzed into the Europa League semi-finals with a 4-1 defeat of Union Saint-Gilloise, sealing a 5-2 win on aggregate.

Xavi Alonso's Leverkusen went into Thursday's quarter-final second leg without a win in their past three visits to Belgium in European matches but the Bundesliga side got the job done.

Moussa Diaby's coolly taken goal settled their nerves in the second minute, with Mitchel Bakker drilling in from close range to double the visitors' lead before half-time.

Bakker played a key role in Leverkusen's third, pressuring Union goalkeeper Anthony Moris into a dreadful clearance which was turned into an empty net by Jeremie Frimpong following what had been a bright start to the second half from the hosts.

Union got their reward for a spirited response when Casper Terho pulled one back with a deflected strike but it proved to be only a consolation, with Adam Hlozek on hand to add further gloss to Leverkusen's win late on.

Leverkusen are into their first European semi-final since making the last four of the Champions League in 2002.