Second-seeded Gilles Simon and number three defending champion Dmitry Tursunov both booked spots in the second round of the Indianapolis Championships Monday with a pair of wins over countrymen.
France's Simon, winner of a third career title on clay in Casablanca in May, was tested by the steamy summer conditions of the US Midwest as he overcame 2006 quarter-finalist Nicolas Mahut 6-2, 3-6, 6-3.
"The first set was great for me, but in the second, I was feeling the heat," said Simon, 26th in the world. "Every shot was difficult."
Simon is to play Benjamin Becker in the second round after the German beat Kristian Pless of Denmark 6-3, 6-4, the dpa reported.
Holder Tursunov is eager to damp down his own repeat title chances but couldn't disguise his desire as he staged a comeback to beat doubles partner Igor Kunitsyn 6-3, 7-5.
Tursunov, whose last title in Sydney in January failed to set the stage for a solid 2008 season, said he could not consider himself a title favourite.
"I don't really feel like the defending champion, and I don't think people expect me to be the guy to win with James [Blake] and [Tommy] Haas in the field," the laid-back number 33 said.
"But surprise can happen," said Tursunov, who beat Canadian outsider Frank Dancevic in last year's final after predictions of a Blake-Andy Roddick title clash were put to rest earlier in the week.
"There is no pressure on me," Tursunov said after coming back for victory as he erased a 4-1 deficit against Kunitsyn in the second set. "It's the others who build it up. I'm not really thinking like the champion right now. The key for me is not to get upset."
Robby Ginepri, the 2005 champion, was beaten for the second-straight year in the first round, going down to Chile's Paul Capdeville 6-4, 6-2 as he lost serve six times.
Capdeville was the second-straight Chilean to humiliate Ginepri after Fernando Gonzalez put the American out in the Wimbledon first round in straight sets.
Australian qualifier Joe Sirianni earned his first ATP-level victory since winning a round at Queen's Club as he benefited when Russian Mikhail Ledovskikh had to quit with an ankle injury in a 6-3, 1-2 loss.
Taiwan's Lu Yen-Hsun won a pair of tiebreakers as he defeated American Justin O'Neal 7-6 (7-2), 7-6 (14-12).