Frenchman Jo-Wilfried Tsonga couldn't maintain his Rogers Cup form and crashed out in the opening round of the Cincinnati Masters, while world number one Novak Djokovic and third seed Stanislas Wawrinka made winning starts in Mason.
Tsonga was quickly brought down to earth by Russian Mikhail Youzhny in straight sets, as the Toronto Masters champion struggled in the entire match. The French player was broken four times and only managed to win seven points on his second serve.
The 29-year-old was expected to challenge for the title, after his stunning victory over Roger Federer in the Toronto final, but failed to make his 12th appearance in Cincinnati count and surrendered the match 6-1, 6-4.
"It's never easy," said Tsonga. "You have to get used to the conditions really quick... I just gave everything on court, but I didn't have enough today to compete at the good level."
Meanwhile, top seed Djokovic faced a stiff challenge from Gilles Simon of France in the second round but the Serbian managed to clinch the encounter 6-3, 4-6, 6-4.
The four-time finalist won the opening set comfortably but failed to maintain the rhythm in the second. Simon rallied back from a 2-1 deficit to make it four-all by getting the break back and forced the decider by converting a second set point.
The Frenchman continued his impressive showing in the third set but after saving six break points, he eventually fell behind 3-4. Djokovic saved a break point in the eighth game, and after a slight rain delay, registered his eighth successive victory over Simon.
"I think I did well for the most of the match," said Djokovic, who will next face the winner between Sam Querrey and Tommy Robredo. "End of the second, start of the third wasn't that great, but I try to take positives from every match. I know I'm not playing at the level yet where I want to be and it's obvious, but I keep on pushing myself.
"Every day is a new challenge to try to look out for a better game tomorrow and after tomorrow, and hopefully it's going to come."
In another second round match, Wawrinka bounced back from his disappointing Toronto Masters third round exit to register a straight set victory over Benjamin Becker of Germany. The 2012 finalist played quite well, winning 82 percent points on his first serve and converting two break points.
The Swiss faced little trouble in winning the opening set but the German took the second into the tiebreaker, which Wawrinka won to register a 6-3, 7-6 (5) victory. Wawrinka will next either face Croatian Marin Cilic or Spaniard Fernando Verdasco in the Round of 16.