Barcelona thumped visiting Borussia Dortmund 4-0 in their Champions League quarterfinal first leg on Wednesday after Robert Lewandowski scored twice against his former club to earn the Catalans a sizeable lead ahead of next week's return visit to Germany.

Undefeated since late December, treble-chasing Barca predictably dominated the opening stages and grabbed the lead with Raphinha's strike in the 25th minute. A string of saves from Dortmund goalkeeper Gregor Kobel frustrated Barca for the remainder of the first half.

Barcelona emerged more determined after the break, and it took only three minutes to score the second goal, with Raphinha assisting Lewandowski, who nodded home from close range.