Rafael Nadal beat Stan Wawrinka 6-1, 6-4 on Friday to reach the Monte Carlo Masters semifinals, where he will face Andy Murray again.Roger Federer lost 3-6, 6-2, 7-5 to Frenchman Jo-Wilfried Tsonga, despite being two points from victory when leading 5-4 in the decider with Tsonga 15-30 down on his serve.This was Federer’s comeback tournament after more than two months out following arthroscopic surgery on his left knee for torn cartilage, and the defeat was softened by relief at coming through the tournament unscathed.”It was good to play back-to-back, yesterday and today, good to play 2 hours 10 (minutes) today,” Federer said. “It was nice to play an intense match. I’m happy how the body reacted.”With Federer, top-ranked Novak Djokovic and Wawrinka – the French Open champion – all out, Nadal will be favorite to win a ninth Monte Carlo title.”He is still a major player on clay,” Federer said of Nadal, whose last title here came in 2012.In a one-sided contest between former champions, Nadal broke Wawrinka four times, and made the semifinals for the 11th time.”I defended well, I moved well,” Nadal said. “When I had the opportunity, I was trying to control the point.”Murray took out Milos Raonic 6-2, 6-0 for the second time this year.”If I play like I did today, I’ll have a chance,” said Murray, who lost to Nadal in the semifinals in 2009 and 2011 when Nadal was winning eight consecutive Monte Carlo titles.Murray beat Nadal in the Madrid Masters final last year, when he won his first two career titles on clay.advertisementMurray, who trails Nadal 16-6 overall in career meetings and 6-1 on clay, thinks patience will be the key factor against the nine-time French Open champion.”He can make you go for winners from uncomfortable positions,” said Murray, who did not face a break point against the big-serving Raonic. “You have to not allow that to happen.”Nadal improved to 15-3 in career matches against Wawrinka, who began as a winner in three of their last five contests.Having saved 15 of 17 break points in the third round against Dominic Thiem, Nadal conceded only one chance this time.Wawrinka drew jeers from the crowd in the fifth game of the first set when he broke his racket, angrily bending it around his thigh.The Swiss player was also frustrated by the noise level coming from people enjoying their lunch in the restaurant perched above center court.”I don’t believe they saw a lot of the match … I think they also drank a lot of alcohol,” Wawrinka said. “When you don’t play well and you’re not in your match, it can bother you.”Nadal had a more moderate view, saying it has been “the same story every day (since) I came here for the first time in 2003.”Following his countryman Wawrinka onto center court, Federer looked like beating Tsonga for the 12th time in 17 matches.But after holding serve in a tense 10th game of the deciding set, the eighth-seeded Tsonga hit two powerful winners off his backhand and forehand to break Federer for the fifth time.Serving for the match, Tsonga gave Federer another opening when he trailed 30-0, and again at 30-30 when Federer missed an easy volley at the net and swiped the ball into the crowd in frustration.Federer’s timing was off and he rushed a forehand on the first match point, giving Tsonga his sixth career win against Federer and his second in their four contests on clay.But for Federer, who has 17 majors among 88 career titles, this defeat took a back seat to his recovery.”It was unfortunate because I had my chances,” said Federer, who beat Tsonga in the quarterfinals here two years ago. “But in this tournament, (it) really doesn’t matter at all if I missed those chances.”Tsonga, meanwhile, next faces countryman 13th-seeded Gael Monfils, who beat Spaniard Marcel Granollers 6-2, 6-4.