Roger Federer was knocked out of the Monte Carlo Masters when he slumped to a 3-6 6-2 7-5 defeat by local favourite Jo-Wilfried Tsonga in the quarterfinals on Friday.
The Swiss third seed, back in action this week after a 10-week layoff, started brightly as he breezed through the opening set but Tsonga, targeting Federer's forehand, played tighter and levelled with a strong display in the second.
The Frenchman broke in the 11th game of the decider with a passing shot winner and he closed it out on serve on his first match point to set up a meeting with compatriot Gael Monfils, who beat Spain's Marcel Granollers 6-2 6-4.
Earlier, there were glimpses of the formidable Rafa Nadal as the eight-time champion swept aside reigning French Open champion Stan Wawrinka 6-1 6-4.
The Spaniard, who set a tournament record of 46 wins in a row in the principality from 2005 to 2013, will take on Andy Murray for a place in the final.
Fifth-seeded Nadal, who broke decisively in the ninth game of the second set, is yet to win a title this year.
"It's exactly what I need, it's what I'm looking for, it gives me confidence," Nadal said.
World No.2 Murray raced into last four with a 6-2 6-0 demolition of Canadian Milos Raonic.
Opening proceedings on centre court, the Briton, who struggled in the previous round, was never bothered by 10th seed Raonic in a one-sided match.
Murray, who hit 19 winners and did not face single break point, has been beaten twice by Nadal in the semifinals of the first clay-court Masters of the season.
(with agency inputs)

Roger Federer reacts during his match against France's Jo Wilfried Tsonga at the Monte Carlo. AFP