Cincinnati [US], August 19 (ANI): Madison Keys toppled reigning World No.1 Iga Swiatek in the third round of the Western and Southern Open on Thursday.

Keys registered a 6-3, 6-4 straight-set victory over Swiatek to enter the quarterfinals.

Keys took 10 games in a row in the middle of the match after Swiatek led 3-2 in the first set. The first six games went with a serve--in which Keys erased the only break point either player shot, in the fourth game--and soon found herself ahead, 6-3, 5-0.

It was then that things got complicated. Swiatek kept a match point to save the bagel and won 11 of 12 points to tighten the scoreboard to 6-3, 5-3, but Keys produced a stunning comeback in the second set to close out the match with a win.

Most notably though, Keys handed the World No.1 her second third-round beating in a row after she was defeated by Brazil's Beatriz Haddad Maia in Toronto last week.

"It feels great. I obviously have not had the best success against World No. 1s, so being able to get a win against Iga, especially after having two losses to her already, means a lot to me, and I think I'm playing some pretty good tennis," WTA.com quoted Keys as saying.

"I was really just thinking that I had to focus a lot on why I got in the position of being up 5-Love. I think I backed off a little bit, and I think she started playing better," Keys said.

"I just knew that I was going to have to try to put some pressure on her early in the game just to kind of also make her aware of the situation. All of a sudden it's 5-4 and she feels like she has to hold that game. So just really trying to swing at the ball, make sure I was moving my feet and put as much pressure on her as quickly as possible," she added.

Later in the day, World No.25 Elena Rybakina has not lost a set in Cincinnati and pushed through another straight-set victory, this time 6-2, 6-4 over Alison Riske-Amritraj to also reach the quarterfinals.

On the other hand, No.8 Jessica Pegula ended Emma Raducanu's campaign at the WesternSouthern Open, beating the US Open champion 7-5, 6-4 in the Round of 16. The top-ranked American advanced to her fourth WTA 1000 quarterfinal of the season. (ANI)