CINCINNATI (AFP) - Wimbledon champion Petra Kvitova crashed out of the second round of the WTA and ATP Masters hardcourt tournament on Wednesday in another setback to her US Open preparations.
Ukrainian teenager Elena Svitolina toppled the third-seeded Czech 6-2, 7-6 (7/2).
Kvitova's exit in her first match after enjoying a first-round bye came a week after a third-round exit on the hardcourts of Montreal, and the world No. 4 admitted she couldn't find her way against the Ukrainian, who is playing her first tournament since defending her title at Baku last month.
"I can still find moments when I really don't know what's happening out there," admitted Kvitova. "Even if I'm older and have more experience, I can still have days like today."
Kvitova held a 3-0 lead in the second set as the Czech attempted a comeback effort. But Svitolina, ranked 39th in the world, nudged the scoreline back to a 5-4 lead only to be broken as she served for the victory.
The pair traded two more breaks before the tiebreaker, where Svitolina claimed victory on the first of four match points as Kvitova mis-hit a return wide.
"From the beginning I didn't feel very comfortable out there," Kvitova said. "And I was trying to really fight, I just wasn't able to do that today."
In men's action, Andy Murray began his final preparation tournament for the US Open, which starts on Aug 25 at Flushing Meadows, with a smooth 6-3, 6-3 victory over Portugal's Joao Sousa on Wednesday.
The eighth-seeded Murray, who lifted the Cincinnati trophy in 2008 and 2011, is searching for his first title since winning Wimbledon 13 months ago.
Since returning in January from back surgery, Murray has enjoyed only modest results, with his best 2014 showings semi-finals at Roland Garros and Acapulco.
Both of the Scot's Cincinnati titles came in finals against Novak Djokovic, the top seed who has won every Masters 1000 title save this one.
Murray improved to 3-0 over the 37th-ranked Souza, never trailing in the match that lasted 71 minutes.
He handed Souza his 21st loss of the season in either the first or second round, advancing on his first match point when Souza sent a service return long.
Murray broke Souza three times, and fired 16 winners matched by 16 unforced errors.
"I got the win and that's the most important thing," Murray said. "It's very different conditions here this week.
"A lot of guys struggle to control the ball, I was happy to come through.
"Conditions are completely different here to Toronto. But I hit the ball well from the back of the court today. I was able to control the ball well.
"That was the most pleasing thing about the match today, because I have seen a lot of the players have struggled so far." Two of the men's top eight seeds fell Wednesday.
Taiwan's Lu Yen-Hsun stunned Czech fourth seed Tomas Berdych 3-6, 6-3, 6-4 while Poland's Jerzy Janowicz upset number seven Grigor Dimitrov 6-4, 3-6, 6-3 four days after the Bulgarian played a semi-final in Toronto.
On the women's side, German sixth seed Angelique Kerber made it safely into the third round with a 6-4, 6-1 win over Ekaterina Makarova of Russia.