PARIS >> A point from losing the first set of his French Open quarterfinal, Roger Federer shanked a routine forehand, sending the ball 10 feet beyond the opposite baseline.

The Court Philippe Chatrier crowd roared with approval, then loudly chanted the last name of Federer’s opponent, Frenchman Jo-Wilfried Tsonga.

That shot was a clear indication that Federer was hardly Federesque on this day. There were plenty of others: He argued with the chair umpire about a call. He dumped overhead smashes into the net. And in a truly rare ungraceful moment, he failed to put a racket to — or get out of the way of — a backhand flip by a sliding Tsonga, instead getting hit on the back.

All in all, Federer looked lost out there Tuesday against the sixth-seeded Tsonga, who pounded his way to a 7-5, 6-3, 6-3 victory over the 17-time Grand Slam champion in a 1-hour, 51-minute mismatch remarkable for its lopsidedness and brevity.

“I struggled a little bit everywhere. To be honest, personally, I’m pretty sad about the match and the way I played. But that’s how it goes. I tried to figure things out, but it was difficult. And Jo does a good job keeping the pressure on,” Federer said.

“He was just … better in all areas,” continued Federer, whose lone French Open title, in 2009, allowed him to equal Pete Sampras’ then-record of 14 major championships. “He returned better than I did. Served better than I did. I struggled to find my rhythm.”

While Federer quickly faced a big deficit Tuesday and never recovered, Serena Williams was able to get out of a much smaller spot of trouble.

Like Federer, Williams is 31. Like Federer, she’s won more than a dozen Grand Slam titles, 15. And like Federer, only one of those trophies came at Roland Garros, in 2002. Trailing in the third set against 2009 French Open winner Svetlana Kuznetsova, the No. 1-seeded Williams won five games in a row en route to a 6-1, 3-6, 6-3 victory that put her back in the semifinals at Paris after a decade’s absence.

Williams had lost four consecutive quarterfinals at Roland Garros — in 2004, 2007, 2009 (to Kuznetsova), 2010 — and so when she was serving while down 2-0 in the final set Tuesday, “I thought, you know, ‘Can’t go out like this again.’ ”

That was a pivotal game, featuring 16 points and three break chances for Kuznetsova, who flubbed the last with a drop shot that floated wide. After finally holding in that game with an inside-out forehand winner as Kuznetsova stumbled to the clay, Williams broke right away with a backhand winner that had her yelling and shaking her fist.

“Unbelievable competitor,” Kuznetsova said. “She turns on (her) game when she needs it.”

Since a first-round exit at Roland Garros a year ago, Williams is 72-3, and she’s currently on a career-long 29-match winning streak. In Thursday’s semifinals, she’ll face No. 5 Sara Errani, last year’s runner-up to Maria Sharapova. Errani reached the semifinals for the third time in the past five major tournaments by beating

No. 4 Agnieszka Radwanska 6-4, 7-6 (6).

Williams is 5-0 against Errani.

Next for Tsonga will be No. 4 David Ferrer, who stopped the wild ride of No. 32 Tommy Robredo 6-2, 6-1, 6-1 in an all-Spanish quarterfinal. Ferrer reached his sixth major semifinal; he has yet to win one.

Noting that Tsonga so easily beat Federer, Ferrer said: “I was a bit surprised.”

Federer hadn’t lost in straight sets before the semifinals at any Grand Slam tournament since a third-round defeat against Gustavo Kuerten in the 2004 French Open.

Starting a month later, when he won Wimbledon, Federer began a stretch of nearly eight full years in which he was unbeaten in Grand Slam quarterfinals, reaching the semifinals at a record 23 major tournaments in a row. Since that run ended, though, quarterfinal exits are becoming a regular occurrence: He has lost at that stage in five of the past 13 Slams, twice to Tsonga, who was the runner-up at the 2008 Australian Open and is trying to give France its first men’s champion at Roland Garros since Yannick Noah 30 years ago.

“Everybody’s expecting a lot from me,” Tsonga said.

“Give him credit: He’s playing in his home Grand Slam, in the quarterfinals, against … the all-time great, and was a break down at the start of the first set. And then was able to stick with it,” said Roger Rasheed, who began coaching Tsonga last October.

Federer had won nine of their previous 12 matches. When they met at the net for a handshake after this one, Tsonga kiddingly thanked Federer for letting him win this time, and both men chuckled.

“Sports, it’s beautiful, because you can always do something.  Even if you play, you know, the best player in the world … you have a chance,” Tsonga said. “Because the guy in front of you (has) two legs, two arms, one head.”