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."
Kuznetsova winced a few times after slow serves, and said afterward she strained an abdominal muscle earlier in the tournament.
"I did push her to the limit, I think, today, even without my serve," Kuznetsova said. "I was serving like, I don't know, a grandmother."
It was the first challenge of the tournament for Williams, who lost 10 games against Kuznetsova after dropping that same number across her first four rounds combined.
"When you don't have tough matches, once you have one, then you are a bit shocked, you know? You don't react well immediately all the time," said Williams' coach, Patrick Moratouglou. "But I'm very proud of her, because she was really, really in a bad situation."
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 last five major tournaments by beating No. 4 Agnieszka Radwanska 6-4, 7-6 (6).
Williams is 5-0 against Errani.
"She forces you to play at a very high level to have any chance of winning. I'll have to hit shots hard and deep and make her move," said Errani, who was 0-28 against women ranked in the top five before Tuesday. "As soon as you hit a short ball, Serena gets right on top of you, and she has enough power to end the point."
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. Robredo won each of his previous three matches despite dropping the first two sets, the first man since 1927 to do that a Grand Slam tournament.
"I wasn't 100 per cent ready to fight" on Tuesday after so many lengthy matches, Robredo said, adding: "And playing with a guy like David, who is a machine, it's very tough to be like that."
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.
The other quarterfinal setback against Tsonga came at Wimbledon in 2011, when Federer lost for the first time in 179 matches after taking the opening two sets.
"He's got a big game. He takes time away from you," Federer said. "He can change defence to offence very quickly. Similar traits to what I have, I guess, really."
Quite a compliment.
This is someone who reached 10 straight Grand Slam finals from 2005-07, winning eight titles. He also appeared in eight major finals from 2008-10, winning four. But since that run ended, Federer has played in two of the last 13 Slam title matches, winning one, Wimbledon last year.
He actually began well Tuesday, leading 4-2. But that's where he got broken for the first of six times by Tsonga, who let four match points slip away in a quarterfinal loss to Novak Djokovic at Roland Garros in 2012.
"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 struggled in the fourth round Sunday against another Frenchman, 15th-seeded Gilles Simon, taking an awkward tumble and falling behind 2-1 in sets. But Federer said after Tuesday's loss he was fine physically.
His game was not fine, not at all, on this day. And Tsonga took full advantage.
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."
These days, Federer sure does seem more human on a tennis court than he used to.
Follow Howard Fendrich on Twitter at http://twitter.com/HowardFendrich