Five-time European champions Barcelona reached their first Champions League semifinal in six seasons with a 5-3 aggregate victory despite being beaten 3-1 by Borussia Dortmund on Tuesday.

Serhou Guirassy scored a hat trick for Dortmund to condemn Barça to their first defeat in 24 games across all competitions this year, but that could not prevent the Catalans from reaching the last four for the first time since 2019.

Barcelona will play either Inter Milan or Bayern Munich, who face each other Wednesday, in the last four.

"Dortmund did very well. We did not have our best day. I had a feeling something like that would happen today because I know the stadium well," Barcelona coach Hansi Flick said.

"Things didn't go too well for us but Dortmund played very well. But congratulations to my team, we're in the semifinals. We're happy. I'm really happy for the team and the club."

The visitors found themselves on the back foot from the start with Dortmund shooting out of the blocks as they attempted to bounce back from last week's 4-0 first-leg loss.

Dortmund, who drew 2-2 against Bayern Munich in the Bundesliga on Saturday, had two golden chances in the opening minutes before Guirassy's chipped penalty in the 11th minute gave them a deserved lead.

The Spaniards, unbeaten in 2025 going into the game, gradually fought their way back and could have levelled were it not for some sloppy finishing from Jules Koundé in the 40th.

After the break, however, Dortmund were again the stronger side at the start and Guirassy headed in after Ramy Bensebaini's nod from a corner four minutes after the restart to ignite hopes of a potential record-matching comeback.

Dortmund's attempt to match Barcelona's Champions League record of overturning a four-goal first-leg deficit in a knockout stage was derailed by Bensebaini's 54th-minute own goal that settled Spanish nerves.

Robert Lewandowski had put Bensebaini under pressure as he chased a cutback from Fermín López, and the Dortmund player stabbed the ball into his own net.

Lopez then had a chance to score himself in the 64th but his shot missed the target.

Guirassy, the first Dortmund player to score 13 goals in a single Champions League campaign, completed his hat trick in the 76th, pouncing on a defensive error by Ronald Araújo.

But with Dortmund still needing two more goals to take the game to extra time, the hosts gradually ran out of steam.

"We wanted to play better and more courageously and support each other more on the pitch," Dortmund's Pascal Gross said. "We did that today and it was a completely different game. It's a shame we didn't play like that in the first leg as we could have got something out of it."