Monaco: Novak Djokovic dropped serve four times before beating Robin Haase 6-4, 6-2 to reach the Monte Carlo Masters semi-finals 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 .

"Today was a difficult match. I'm happy about the way that I played," said Nadal, who next faces Gilles Simon of France.

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.

The ninth-seeded Simon beat No. 4 Jo-Wilfried Tsonga 7-5, 6-4 in an all-French match.