Iga Swiatek’s US Open run has come to an end.

The defending champion and world No. 1 lost in three sets in the Round of 16 Sunday to Jelena Ostapenko, who remains undefeated against Swiatek in her career. The loss means that Swiatek’s stay atop the WTA world rankings will end next week. Current No. 2 Aryna Sabalenka will overtake the top spot for the first time.

“I don’t know why I played that bad,” Swiatek said. “I’m not happy with my performances on hard courts this year. But overall, I did a pretty good job at maintaining my level. I’m happy I’m going to have time to practice because I miss that.

“I feel like I’m progressing as a player, but I have more skills. This season was tough and intense.”

Swiatek’s 75 consecutive weeks atop the world rankings in her first stint ranks third in history. Only Steffi Graf (186 weeks) and Martina Hingis (80 weeks) were atop the rankings for longer.

According to OptaJack, during that time Swiatek also holds the record for WTA titles (nine), finals (12), matches won (97), winning ratio (85.5 percent) and top-10 defeats (17).

“I wouldn’t say [I feel] relief,” Swiatek said, when asked about relinquishing the top spot in the rankings. “There are plenty of things that I know I should have done differently. Maybe I’m not mature enough yet to do that. I’m really working hard to not think about this stuff a lot.

“Sometimes when you force yourself not to think about stuff, the result is the opposite. I’m really happy that I have smart people around me and they are telling me how to do it, and they are guiding me. But it’s on me to actually make it happen.”

Still, the 22-year-old Polish star said that the next time she tops the rankings, she will do some things differently.

“Because yeah, it was a little bit stressful,” Swiatek said. “And it shouldn’t be. I mean, tennis is stressful overall, but I should embrace it a little bit more. And I’ll do it differently next time.”