NEW YORK (AFP) - Czech third seed Karolina Pliskova, chasing her first Grand Slam title, advanced to the fourth round of the US Open on Friday (Aug 30) by outlasting Tunisia's Ons Jabeur 6-1, 4-6, 6-4.
Pliskova, the 2016 US Open runner-up who could finish the fortnight as world number one, booked a spot in the last 16 against either British 16th seed Johanna Konta or China's 33rd-seeded Zhang Shuai.
After taking the first set in 26 minutes, Pliskova broke to open the second. Jabeur, ranked 62nd, had her right knee retaped and battled back to break Pliskova three times in the second set, the last on a forehand winner to force a third set.
Pliskova broke to start the third set and seized another in the fifth game on an errant Jabeur forehand before advancing on a backhand winner after two hours and eight minutes.
"She improved the game a lot in the second set, she hit a couple unbelievable shots and got into her rhythm," Pliskova said.
"Especially had to serve well. Was able to hit a couple aces in the third set which really helped. Physically it was quite a tough battle. It was important to win so it doesn't matter how I feel. So pleased to be through."
Pliskova, 27, is battling top-ranked defending champion Naomi Osaka of Japan and Australia's second-ranked Ashleigh Barty, the French Open winner, for the world number one spot.
Barty, who faces Greek 30th seed Maria Sakkari later, has the inside track because Osaka has so many points to defend.
Osaka must win the title to have any chance at staying on top while Pliskova must reach at least the semi-finals.
Former world number one Serena Williams resumes her quest for a 24th career Grand Slam title to equal Margaret Court's all-time record when she meets 44th-ranked Czech Karolina Muchova in a third round matchup at Arthur Ashe Stadium.
The 37-year-old American, six times a US Open champion, has been a runner-up in three of the past five Slams, falling to Osaka in last year's US Open final. She last won a Slam crown at the 2017 Australian Open while pregnant and hasn't won the US Open title since 2014.
Top-ranked defending champion Novak Djokovic and 20-time Grand Slam winner Roger Federer were set to make their bids to reach the last 16 later Friday.
Federer, who faces Britain's 58th-ranked Dan Evans, last failed to reach the fourth round at a Slam in the 2015 Australian Open. The 38-year-old Swiss star missed the US Open last 16 only in his 2000 debut.
Djokovic, who has won four of the past five Slam titles and 16 overall, was set to play 111th-ranked American Denis Kudla, who has never beaten a top-10 rival in 10 tries.
The 32-year-old Serbian, a three-time US Open winner, has been no worse than a US Open semi-finalist since a third-round exit in 2006.
Also looking to reach the fourth round was Japanese seventh seed Kei Nishikori, who played Australia's Alex de Minaur. The 38th-ranked Aussie has never beaten a top-10 foe in 11 prior tries.