MONACO -- Fifth-seeded Juan Martin del Potro, sixth-seeded Jo-Wilfried Tsonga and No. 7 Richard Gasquet all advanced to the third round of the Monte Carlo Masters on Tuesday.
Tsonga beat Russian veteran Nikolay Davydenko 7-6 (3), 6-2, while Gasquet had a little more trouble overcoming Benoit Paire 6-1, 3-6, 6-1 and Del Potro was pushed even further as he struggled past Alexandr Dolgopolov of Ukraine 1-6, 6-4, 6-3.
Del Potro, who received a wild card invitation to play, was broken twice in the first set and came back from a break down to edge a scrappy second set which saw the players share five breaks of serve. The big-serving Argentine next faces either 12th-seeded Milos Raonic or Jarkko Nieminen.
"I wasn't ready in the beginning of the match, I was trying to play long rallies, but he play fast," Del Potro said. "I was trying all the time to feel better on court with my forehands and backhands. I found that in the end of the match."
Tsonga, meanwhile, overcame a shaky start against Davydenko, whose ranking rose to No. 3 in December, 2006.
"It was a pretty good start, but I can do better. I got broken from the start," said the 27-year-old Tsonga, who won his 10th career title at the Open 13 in Marseille earlier this year. "But I did play a solid match and I was able to manage the situation quite well. I'm happy I won because he can be a very dangerous player, he's proven it in the past."
No. 8 Janko Tipsarevic went out, losing to Grigor Dimitrov of Bulgaria 7-6 (3), 6-1.
Gasquet broke Paire twice in the third set and set up a match against either No. 9 Marin Cilic of Croatia or big-serving Kevin Anderson of South Africa, who .
"That was an important match to win," said Gasquet, who is still bothered by a sore ankle that forced him to skip France's Davis Cup quarterfinal loss to Argentina recently. "I'm happy I won the first round because now I'm only playing Thursday."
Paire levelled the match when he broke Gasquet with a superb cross-court backhand pass and then served out the set.
"For sure he played better than me in the second set, I lost five games in a row," Gasquet said. "He was being more aggressive and I was playing a little bit short."
Dimitrov had seven aces and broke Tipsarevic's serve four times.
"It's never easy playing against Janko. I played him three times before, always losing in close matches," said Dimitrov, who faces either Florian Mayer or Roberto Bautista Agut in the third round. "I fought until the last point in the first set. I gained an extra edge as the match goes on."
Philipp Kohlschreiber of Germany also advanced to the third round, while Stanislas Wawrinka of Switzerland, Nicolas Almagro of Spain, Juan Monaco of Argentina, Marinko Matosevic of Australia and qualifier Albert Ramos of Spain advanced to the second round.
American John Inser, who won the U.S. Men's Clay Court Championship on Sunday for his first title on clay, failed to continue his winning streak as he lost 4-6, 6-2, 6-3 to Latvia's Ernests Gulbis.
"I'm not trying to make excuses, but, yeah, I was a little tired. That's to be expected," Isner said. "But at the same time, you know, I won the first set. I don't know, I think it was 2-all or something and I just sort of fell apart."
Top-ranked Novak Djokovic, who drew a crowd for a practice session on an outside court, is set to play after recently twisting his ankle. He takes on Mikhail Youzhny of Russia.
In other second-round matches Wednesday, second-seeded Andy Murray plays Frenchman Edouard Roger-Vasselin and eight-time defending champion Rafael Nadal, who is seeded third, will face Matosevic.