Carlos Alcaraz has apologised for his behaviour during Friday afternoon’s loss to Gael Monfils at the Cincinnati Open.

Alcaraz repeatedly smashed his racket on the court in a rare show of frustration on Friday, and the four-time Grand Slam winner fell to Gael Monfils 4-6, 7-6 (7-5), 6-4 at the Cincinnati Open.

Posting in Spanish on X on Saturday, Alcaraz said his attitude was not correct, and his actions should not have been done on the court. The 21-year-old added that it’s difficult to control yourself when your heart rate is high, and he will work to ensure it doesn’t happen again.

In a match that was suspended by rain on Thursday night with the players in a second-set tiebreaker, the 37-year-old Monfils advanced by taking the last two sets from the second-seeded Alcaraz, who called the loss his “worst match”.

“I felt like it was the worst match that I’ve ever played in my career,” Alcaraz said. “I’ve been practicing really well. I was feeling great. But I couldn’t play. I want to forget it and try to move on to New York.”

Trailing 3-1 in the tiebreaker when the match was halted, Alcaraz was hoping for a reset when play resumed Friday. However, the No. 3 player in the ATP rankings couldn’t control his emotions.

“It never happened before, because I could control those feelings,” Alcaraz said. “Today I couldn’t. I was feeling that I was not playing any kind of tennis. It was really frustrating for me.

“At some point, I didn’t want to be on the court any more.”

Alcaraz was playing his first match since earning a silver medal at the Paris Olympics after losing to Novak Djokovic, who also beat him last year in the Cincinnati final.

The US Open begins there on 26 August.