Mason: France`s Jo-Wilfried Tsonga looked back to full fitness while Czechs Tomas Berdych and Radek Stepanek came through their first tests at the Cincinnati Open.
Wimbledon semi-finalist Tsonga defeated Croat Marin Cilic 6-3, 6-4 in the opening round, dropping just six points on serve and hitting nine aces.
Tsonga had been suffering from an arm injury which caused him to withdraw during the semi-finals of the Montreal Masters last week but he looked to be striking the ball without any hindrance.
"I didn`t play the last two days because of my arm, and this morning at the warmup I was feeling really good. It was a really fluid match. Everything was easy for me today, including my serve," Tsonga said.
The Frenchman pulled out of his tie against Novak Djokovic last week in Canada where the Serb went on to win the tournament.
Berdych, the eighth seed, breezed through his second round match against Argentine Juan Monaco in straight sets 7-6, 6-0, winning 83 percent of first serve points.
Compatriot Stepanek, who entered here as a qualifier, came out on top against big-serving American John Isner 7-5, 5-7, 7-6 in a tough first-round encounter lasting two hours and 46 minutes.
Stepanek triumphed, despite 21 aces from Isner, and the Czech saved three break points in the final set.
World number three Roger Federer is the first of the top four to feature in the tournament when he faces Argentine Juan Martin Del Potro later on Tuesday.