CINCINNATI, Ohio: Olympic champion Andy Murray was sent crashing out of the Cincinnati Masters on Thursday, falling 6-4, 6-4 to French lucky loser Jeremy Chardy.

Britain’s Murray won a match in Toronto last week before quitting with a knee injury but had looked impressive in his opener here against American Sam Querrey. But the 25-year-old Murray was distinctly under-cooked against Chardy and his 16th unforced error of the second set sent the Frenchman into the last eight.

“This was like my second or third match in the hard court. I played well yesterday; didn’t play so well today,” said Murray.

“Sometimes I’ve won tournaments in the buildup (to a major) and it hasn’t helped me. That doesn’t normally have that much bearing. But I would have liked to have done a bit better this week,” he said, with the US Open on the horizon.

Four-time champion and top seed Roger Federer turned in another flawless performance, schooling Australian teenager Bernard Tomic 6-2, 6-4 with 27 winners.

“Overall I’m happy. But it’s hard to judge my game in these quick conditions,” said Federer, the Olympic silver medallist, who however admitted that his serve was “a bit off.”

“It was a good performance, I’m playing as well as I want to right now,” said the Swiss great.

Second seed Novak Djokovic barely broke a sweat against Nikolay Davydenko, who was nursing a shoulder injury and only lasted 30 minutes before quitting after Djokovic took the first set, 6-0. Davydenko had 10 unforced errors and eight double-faults.

“This is not the way to win a match, it was clear that he was struggling physically,” Djokovic said. “I just hope he will be fit for the US Open.”

Canadian Milos Raonic upset fifth seed Tomas Berdych with 20 aces in a 6-4, 2-6, 6-2 win.

Olympic bronze medallist Juan Martin del Potro, who missed 2010 due to right wrist surgery, had troubles with his left wrist, but pushed through the pain to notch a 7-6 (7/2), 2-6, 6-1 win over Serbia’s Viktor Troicki.

Tenth seed Mardy Fish continued to perform well on his home cement courts, beating Czech Radek Stepanek 6-3, 6-3 with seven aces and 23 winners. Fish will next play Federer.

Recent exertions in winning Wimbledon and Olympic gold caught up with Serena Williams, but the fatigued second seed nevertheless stumbled through into the WTA quarters. The 30-year-old defeated Urszula Radwanska 6-4, 6-3.

“I was tired out there,” said Williams. “I just told myself to try to move my feet a bit, get through this match and go get some rest.”

Top seed Agnieszka Radwanska beat American Sloane Stephens 6-1, 4-6, 6-4, while US Open titleholder Samantha Stosur beat Elena Makarova 6-1, 6-3. Former Wimbledon winner Petra Kvitova, the fourth seed, advanced over China’s Peng Shuai, 6-2, 6-2.

Nadal not worried

if ranking plummets

In Madrid, Spanish tennis ace Rafael Nadal, who pulled out of the US Open due to injury, said yesterday his sole focus now was on getting back to full fitness again and not worrying about his world ranking.

The world No. 3 on Wednesday withdrew from the US Open, the final Grand Slam of the season, which starts in New York on Aug. 27, because of his continuing battle with knee tendinitis.

“Now I’m not bothered if I’m third or fourth in the ATP. The most important thing is to be physically fit,” said Nadal. “I’ve missed too many important tournaments to continue taking risks. I’ll return when my knee is better.

“I’m saddened not to be able to compete in the US Open because it’s a tournament in which I’ve always felt great support but I can’t take risks.”

Nadal won a record seventh French Open title in June but he crashed out in the second round at Wimbledon in a shock upset against Czech Lukas Rosol.

Shortly after the 26-year-old pulled out of the Olympics and subsequently withdrew from ATP Tour events in Toronto and Cincinnati.

The tennis ace’s coach and uncle said on Thursday that Nadal should be ready for the Davis Cup semi-final between Spain and the United States next month.

“It was the right decision. This pause will further prolong his career and, possibly, he will have no more problems in the future,” Toni Nadal told Spanish radio, adding the goal is to work for a “full recovery.”