MASON, Ohio (Reuters) - World number one Iga Swiatek and reigning U.S. Open champion Emma Raducanu were both knocked out of the Cincinnati Open on Thursday, while second seed Anett Kontaveit also had her preparations for Flushing Meadows cut short in the round of 16.
Raducanu had beaten former Grand Slam champions Serena Williams and Victoria Azarenka in the previous two rounds but was brought down to earth with a bump in a 7-5 6-4 defeat by Jessica Pegula, the highest-ranked American at eighth in the world.
“I definitely felt like I was pretty nervous tonight, not really knowing - well, knowing how she plays but not actually practicing or hitting with her,” Pegula said.
Another American, Madison Keys, earlier accounted for Swiatek to take her place in the quarter-finals and register her first win over a reigning world number one.
Swiatek saved four match points but was far from her best as she exited a second tournament in the North American swing at the last-16 stage after last week’s Canadian Open.
Keys had failed to take a set off the Pole in two previous meetings but was far more clinical with her powerful returns and groundstrokes, breaking the world No 1 five times in the 6-3 6-4 victory.
Keys will next face Wimbledon champion Elena Rybakina, who beat Alison Riske-Amritraj 6-2 6-4 to sail into the quarterfinals.
Wimbledon finalist and fifth seed Ons Jabeur also made her exit, ushered out of the door by twice major winner Petra Kvitova 6-1 4-6 6-0.
Kvitova next faces Australian Ajla Tomljanovic, who staged a stunning comeback to beat Russian Veronika Kudermetova 3-6 7-6(4) 6-3 and reach her first WTA 1000 quarter-final.
World No 2 Kontaveit looked to have taken charge of her tie against Zhang Shuai when she won the opening set at a canter but her Chinese opponent dug deep to claim a stunning 2-6 6-4 6-4 upset.
Zhang came from a break down in the third set to upset Kontaveit – her fifth top 5 win overall, and first top 10 win since defeating Angelique Kerber in 2018.
Eighth seed Aryna Sabalenka later takes on Shelby Rogers for a place in the last eight.