Novak Djokovic dropped serve four times before beating Robin Haase 6-4, 6-2 to reach the Monte Carlo Masters semifinals on Friday, saying he had thought about pulling out of the event following his grandfather's death.

Playing the day after his grandfather died, the top-ranked Djokovic looked distracted at times against Haase. He missed a first chance to serve out for the match at 5-1 before breaking the unseeded Dutchman for the seventh time to seal victory.

The win kept Djokovic on course for a final against seven-time defending champion Rafael Nadal, who overcame a slight blip in the first set before beating Stanislas Wawrinka 7-5, 6-4 for his 40th straight win at Monte Carlo.

Fourth-seeded Jo-Wilfried Tsonga was upset 7-5, 6-4 by ninth-seeded Gilles Simon in an all-French match.

Djokovic had considered withdrawing before his third-round match on Thursday, which came only a few hours after he'd received the bad news.

"Yeah, I did. But I'm a professional and life goes on," he said. "I know that I cannot change anything now. Obviously, it's what life gives you and takes (from) you. It's a normal circle of life. I was very close to him, so it was a big loss for me.

"Anytime is the wrong time to receive that news. Today was a bit better, but still a lot of emotional ups and downs throughout the match. I got to the semifinals, which is big result for me under the circumstances."

Because of his tennis commitments, Djokovic will be unable to make the funeral back home in Serbia.

"No, it's not possible. It's a very sensitive thing to talk about really," he said. "Every religion has a different way of proceeding, the funerals, life itself."

Djokovic lost a total of 16 points on his usually rock-solid first serve, and his play was sometimes erratic.

"It's tough to be able to play tennis after the way I felt and the way I still feel," Djokovic said. "I remember him as a great man, and I know he's been supporting me and still from the heavens now."

Djokovic next plays sixth-seeded Tomas Berdych, who took advantage of a wayward performance from Andy Murray to win 6-7 (4), 6-2, 6-3.

"He's a threat to anybody on any surface. Big groundstrokes, powerful serve," said Djokovic, who is 8-1 overall against Berdych but has never played him on clay. "He knows what it feels like to play on the big stage. He had a great match against Andy today."

Nadal followed Djokovic on to the court, broke Wawrinka immediately and then opened up a 3-1 lead.

The six-time French Open champion looked in control at 40-15 in the eighth game, but some uncustomary unforced errors gave Wawrinka a chance and he broke back for 4-4.

Wawrinka briefly led at 5-4 when he fought back again from 40-15 down and held with a strong second serve. Nadal won the next three games to win the set. He set up match point with a pass down the line and closed it out with an ace.

Tennis great Bjorn Borg watched Nadal's victory, then said on television that he considered the Spaniard the greatest player ever on clay.

"Let's wait (until) I finish my career," Nadal said. "My uncle always told me that when Bjorn goes on court, everybody feels that he's unbeatable. I don't know how to explain but I don't have this feeling."

The Swede won six French Opens among his 11 Grand Slam titles. Nadal has won 10 major titles.

Murray had no excuses for losing, having not even completed a set in getting past Julien Benneteau while Berdych was taken to three sets by Kei Nishikori.

"He played very, very well today," Murray said. "Every time I lose a match, I get asked, 'What did you do wrong?' Sometimes the guy plays well."