PARIS -- Roger Federer lost an argument. His tennis was more persuasive.
Miffed by a line call in his first match as French Open defending champion, Federer quickly regrouped to win the opening set two points later and then went on to beat Peter Luczak 6-4, 6-1, 6-2 on Monday.
The top-ranked Federer committed only 11 unforced errors, lost just 14 of 64 points on his serve and faced only one break point.
"It's always important coming back as defending champion trying to get off to a good start," he said. "It was like a perfect match to get off the French Open campaign, really."
This is only the second time in nine years that Federer arrived in Paris without a title during the clay season. But the 16-time Grand Slam champion showed no signs of vulnerability against Luczak, an Australian who fell to 0-4 in French Open matches.
Although Federer won at Roland Garros a year ago to complete a career Grand Slam, the role of favorite again goes to four-time champion Rafael Nadal. They could meet in the final.
"I hope I'll be playing the finals," Federer said. "If it's him, it's perfect."
The unseeded Dent won a match at Roland Garros for the first time in his 12-year career, beating Nicolas Lapentti 6-3, 6-4, 7-6 (3).
"Better late than never, right?" Dent said. "There's nothing more that Americans love than to come over here and win matches. We always have that label, like, 'Oh, you're American. First round, see you later.' So I think we get a lot of pride from winning matches here."
The match resumed at 8-all Monday after being suspended overnight because of darkness.
With temperatures in the mid-80s on a second successive cloudless day in Paris, Federer lost his cool for only a moment. Speaking to the chair umpire in French and wagging his index finger, he disputed a line call on a Luczak serve and then waved his arms in disgust as he walked back to the baseline.
"He got a bit of a rough call against him, actually," Luczak said.
A double fault by Luczak moments later ended the first set, and the match then became a clinic, with a relaxed Federer putting his vast repertoire of shots to full use.
On one point he started behind the baseline, sprinted to chase down a drop shot near the net post, slid into his forehand and flicked it from ankle level cross-court for a winner. He ended a long rally with a sliced backhand that carried so much spin it bounced back toward the net for another winner, and he raised a finger to acknowledge the cheers.
"If it was anyone else, I'd be getting pretty angry," Luczak said. "He just had me on a string and just was toying with me at the end. I think he was enjoying it."
On match point, Federer leaned into a backhand and pulled it at an improbable angle for one last winner, prompting a final "Ahhhhh" from the crowd.
Murray was never in control during the first two sets but Gasquet then ran out of steam and needed massage on his legs after the fourth.
Murray also rallied from two sets down to beat Gasquet at Wimbledon in 2008.
Gasquet missed the French Open last year while serving a 2½-month suspension after testing positive for cocaine.
Gasquet also needed treatment on his legs during the final Saturday in Nice, where he won his first title since 2007.
Djokovic took the first set in just 27 minutes without facing a single break point but lost his serve twice in the second.
Djokovic won 85 percent of the points played on his first serve in the third set and broke Korolev twice.
The former Australian champion then took Korolev's serve to get the first game of the fourth and broke again to close out the match.
Isner, seeded 17th, lost only 10 points on his serve, never faced a break point and beat Andrey Golubev 6-4, 6-3, 6-2. No. 12 Fernando Gonzalez, No. 13 Gael Monfils, 14th seed Ivan Ljubicic, No. 15 Tomas Berdych, 19th seed Nicolas Almagro, 20th seed Stanislas Wawrinka, No. 24 Thomaz Bellucci, No. 25 Marcos Baghdatis and No. 31 Victor Hanescu also won, but No. 27 Feliciano Lopez lost to Julian Reister 6-1, 7-6 (5), 6-2. No. 21 Tommy Robredo also lost, falling 6-4, 6-4, 6-3 to Viktor Troicki.
Information from The Associated Press was used in this report.