(CNN) -- Rafael Nadal is known as the undisputed king of clay with seven French Open titles to his name -- but the Spaniard was given an almighty scare in the quarterfinals of the Monte Carlo Masters Friday.
Nadal, who has won the past eight editions of the tournament, was made to fight all the way by Bulgaria's Grigor Dimitrov before eventually prevailing 6-2 2-6 6-4.
It was the first time the 26-year-old had dropped a set at the tournament since 2009 as he racked up a 45th consecutive match victory in the French principality.
That record had looked in doubt until his opponent began to suffer with cramp in his leg, allowing Nadal to emerge victorious.
But despite working his way back to fitness following a seven month absence with a knee injury, Nadal admits he still lacks match sharpness.
"I didn't play tennis for seven months," he told reporters. "I'm losing little bit intensity of the match for moments.
"That's normal after being a lot of time outside of the competition. I played for a month, then I stopped for another month. I need time to play with top rhythm for the whole match.
"I was playing great at the first set, playing my best level. So that's the most important thing."
Nadal was spotted playing with taping on his back, but he refused to elaborate on the problem when asked.
He added: "I'm happy to be in the semifinals, I played the best with what I had. It's normal have problems on the back, on the shoulder, on the elbow."
Dimitrov, 21, is rated as one of the most exciting prospects in world tennis and for a while looked set to become the first man to defeat Nadal in Monte Carlo since 2003.
The 11-time grand slam winner was given a stern examination by the man ranked 34 in the world, who eventually succumbed after suffering pain in his left leg.
"It's a tough loss, I think I gave everything I had today," Dimitrov told reporters.
"Today he obviously showed why he's the best not only on that surface, I believe, but he's one of the best out there."
Nadal will now face France's Jo-Wilfried Tsonga, who saw off Stanislas Wawrinka 2-6 6-3 6-4 in his quarterfinal tie.
Wawrinka, who defeated Andy Murray in the previous round, fought off four match points before eventually being swept aside.
"It's an incredible challenge," Tsonga told reporters of his upcoming contest with Nadal.
"He's won eight times here. Anything I might achieve will be just a bonus for me.
"I no longer have any pain in my legs, because I know I'm going to play a player that's a lot better than I am on clay.
"I do have some weapons; I have everything to win and nothing to lose."
Top seed Novak Djokovic overcame his troublesome ankle problem to see off Finland's Jarkko Nieminen 6-4 6-3.
"My ankle is getting better and better," Djokovic told reporters.
"The pain is subsiding and that is very important for me. I just hope to play a good match tomorrow."
The Serb will face Italy's Fabio Fognini in the last four after he defeated France's Richard Gasquet in straight sets.