Barcelona thumped visitors Borussia Dortmund 4-0 in their Champions League quarterfinal first leg Wednesday after Robert Lewandowski scored two goals against his old club to earn the Catalans a sizable advantage.

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

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

"I think we played very well, but we are not thinking about the semifinals yet, we must keep the same focus and mentality that have brought us here so far," Lewandowski told Movistar Plus. "It doesn't matter where we play and what game it is, we always want to play our football with the same commitment.

"Our mindset is always going for the win and that is how we will play at Dortmund. We have to go there and play as well as we did today or even better."

Barcelona have enjoyed an incredible 23-game unbeaten run across all competitions and are the only team in Europe's top five leagues yet to lose in 2025, while still in the running to win three titles.

On Wednesday, Dortmund keeper Kobel denied Lewandowski and Lamine Yamal from close range, but there was little he could do when Raphinha fired over the goal line in the 26th minute.

After the break, Yamal made an impressive run from the right wing before lifting a cross toward the back post for Raphinha to head back across goal, leaving an unmarked Lewandowski to nod over the line from inches out.

After that Dortmund succumbed to Barca's power and, following Fermín López stroke off the post, Lewandowski extended their lead with a bullet strike and Yamal rounded off the rout with a tidy finish from a quick counter.