Rafael Nadal extends Monte Carlo winning record to 45
Spain's Rafael Nadal extended his extraordinary unbeaten record at the Monte Carlo Masters to 45 matches with a 6-2 2-6 6-4 win over Bulgaria's Grigor Dimitrov in the quarter-finals.
The eight-time defending champion will now face France's Jo-Wilfried Tsonga, who beat Stanislas Wawrinka.
Novak Djokovic did not seem bothered by his sprained ankle as he overcame Finland's Jarkko Nieminen 6-4 6-3.
The world number one will face Italy's Fabio Fognini in the semi-finals.
Nadal lost a set in the event for only the third time since 2009 but came through to beat Dimitrov, who suffered from cramp in the closing moments of the match.
"I didn't play tennis for seven months. I'm losing little bit of intensity," said Nadal. "That's normal after being outside of the competition for a long time.
"I played for a month, then I stopped for another month. I need time to play with top rhythm all the match.
"I was playing great in the first set, playing my best level. So that's the most important thing."
Dimitrov, 21, managed to save a match point with a winner down the line which left him doubled over in pain.
A few moments later, Nadal hit his second ace of the match to secure the win.
"It's a tough loss, I think I gave everything I had," said Dimitrov. "He obviously showed why he's the best not only on that surface, I believe, but he's one of the best out there."
Djokovic, who picked up a ankle injury while on Davis Cup duty with Serbia less than two weeks ago, was pleased with his physical improvement.
"It's a great step forward for me," he said. "I did not have the feeling that the ankle was bothering me, I was very solid. I elevated the level of my game in the past two matches, definitely."
The day began with last year's Wimbledon semi-finalist Tsonga overcoming Wawrinka 2-6 6-3 6-4 to reach his second ATP Tour semi-final of the year.
The Swiss player, who defeated Andy Murray on Thursday, took the first set before Tsonga eased to 4-1 in the second before levelling the match after saving two break points.
Tsonga broke in the seventh game of the decider with a forehand shot down the line and then held for 5-3. The French player sealed victory in his next service game with an ace.
"Stan made me work for this win as he saved all those match points," said the sixth seed.. "I'm just glad to get to the semi-finals."
Fognini upset French seventh seed Richard Gasquet 7-6 (7-0) 6-2.