Goals from Andriy Voronin 10 minutes before the break and Sergej Barbarez 10 minutes after it set the Bundesliga side up for victory.

Juan rounded off the 4-2 aggregate win with a header in the 70th minute, making Leverkusen the first team in the hat for Friday's quarter-final draw.

The first chance of the game fell to the home side when, after 13 minutes, Tranquillo Barnetta found the outside of the post with a header.

Rene Adler in the Leverkusen goal was called into action after 23 minutes to deny Olivier Monterrubio, who had been put through by Eric Carriere, in the visitors' first real attack.

It was Liverpool-bound Voronin who opened the scoring, controlling the ball with his chest before sweeping a shot past Charles Itandje.

At 1-0, the tie was still on a knife edge but Leverkusen banished any worries in an inspirational second half.

Ten minutes in, Germany international Bernd Schneider, the architect of their defeat of Blackburn in the previous round, was the provider as Barbarez doubled the home side's lead.

Voronin met Schneider's cross with a header which cannoned back off the inside of the post to the feet of Barbarez, who had time to settle himself before placing the ball into the empty net.

Voronin - who will move to Anfield at the end of the season on a Bosman free transfer - forced a spectacular save out of Itandje with an improvised backheel, but Juan left the last line of the Lens defence no chance in the 70th minute.

The Brazilian defender was left unmarked at the far post to head Voronin's corner inside the post for Leverkusen's third and put the German club into the last eight of the UEFA Cup.

Werder Bremen became the second German club to advance into the quarter-finals tonight with a 2-0 win over Celta Vigo.

Hugo Almeida and Clemens Fritz provided the goals early in the second half to complete a 3-0 aggregate win for Thomas Schaaf's side.

Celta, who sent a largely second-string side to northern Germany, rarely looked like overturning the 1-0 deficit from the first leg and, apart from having two Jose Perera goals disallowed, did little to test Bremen goalkeeper Tim Wiese.

It took 40 minutes for the game to come to life, and the first chance fell to the home side with Christian Schulz having two bites of the cherry from Almeida's cross.

His second effort, after he scuffed his first, missed the post by a distance, though.

Just three minutes into the second half, Almeida beat the offside flag and headed Kevin Schindler's cross past Esteban Suarez.

Bremen almost doubled their advantage within minutes when Diego's fizzing shot was pushed wide by Suarez and Naldo then saw a header cleared off the line.

Shortly after, Celta thought they had grabbed a lifeline when Perera headed past Wiese, but the goal was ruled out for offside.

Ten minutes later, Bremen sealed their place in the quarter-finals when Fritz robbed Nene of possession before beating Matias Lequi and placing his shot past Suarez and into the far corner.