"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."
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 quarter-final. Robredo won each of his previous three matches despite dropping the first two sets, the first man since 1927 to do that in a Grand Slam tournament.
"I wasn't 100 per cent ready to fight" 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 quarter-finals, 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 quarter-final setback against Tsonga came at Wimbledon in 2011, when Federer lost for the first time in 179 matches after taking the opening two sets.
- AP