Karen Khachanov stunned World No. 4 Felix Auger-Aliassime in the second round of the US Open on Thursday. With this win, Khachanov has earned his first top-10 win of the ongoing season.

Khachanov registered a 6-7(5), 6-3, 6-2, 6-2 win against the Canadian in three hours and 16 minutes. Aliassime won the opening set but then veered off the track as he wasn’t feeling well. He admitted he was dizzy and was seeing spots after winning the opening set.

“It’s tough to talk about anything other than how I felt physically. After a set and a half, I just couldn’t feel well and was dizzy and seeing spots and couldn’t recover,” Auger-Aliassime said. “I thought maybe it would pass, but it didn’t.”

“I’ve never felt quite like that,” Auger-Aliassime continued. “I’ve had cramps before. I’ve felt tired towards the end of matches, but in a normal way. This was a little bit abnormal, and there were no signs in the last couple of days and no signs this morning, as well. Yeah, I’m not sure. I’m going to run some tests and see what comes out of it.”

Khachanov wished Aliassime a speedy recovery and said he tried to give his best on the court.

“I wish him to feel better and speedy recovery if he is injured, I don’t know. What I can say from my side is I tried to give my best performance,” Khachanov said in his on-court interview. “I was fighting and I am super happy to get this win.”

After reaching the semifinals at the US Open in 2022, this is the first time Khachanov has reached the third round at the tournament.

“The last month didn’t go well for me, so we have been practising and I am sure I am fit,” Khachanov added.” The last tournament of the American swing, with the US Open, coming with the mindset to perform well and to try to take one step at a time.”

Khachanov will either play Peruvian star Ignacio Buse or Frenchman Benjamin Bonzi in the third round.