(CNN) -- World No.13 Gael Monfils has stunned top seed Rafael Nadal by beating the Spaniard 6-4 6-4 to reach the semifinals of the Qatar Open in Doha on Thursday -- the ATP Tour Web site has reported.
Monfils had never previously taken a set off Nadal in their three previous meetings.
The Frenchman, who in three previous meetings had failed to win more than three games in a set against Nadal, produced some excellent tennis and broke the Nadal serve on three occasions in a match lasting 89 minutes.
It was Nadal's first defeat in a completed match prior to the semifinals since May 2008, when he fell to Juan-Carlo Ferrero in the second round at the ATP World Masters event in Rome.
The 22-year-old Monfils is bidding to reach his second final in Doha, having finished runner-up to Roger Federer in the title match in 2006.
The Parisian reached his sixth career final in Vienna last year and reached his first Grand Slam semifinal in front of his home crowd at Roland Garros last May.
Fifth seed Monfils will now face fourth seed Andy Roddick, who was dominant on serve as he defeated Romanian Victor Hanescu 6-3 6-2.
The American made 82 per cent of his first serves, firing 13 aces, and won 76 per cent of points on his serve in the 67-minute encounter.
Roddick improved to a 3-0 career lead over Hanescu, whom he also beat at ATP World Tour Masters events in Paris in 2003 and Rome in 2006.
Meanwhile, Andy Murray set up another meeting with Federer by beating Ukrainian Sergiy Stakhovsky 6-4 6-2 to also move into the last four.
The pair have faced each other five times in the last year, with Murray winning four of those matches but losing the most high-profile one - the U.S. Open final.
Murray, the defending champion, also came out on top last week in the semifinals of the World Tennis Championship in Abu Dhabi, a contest that was the latest in a series of close matches between the duo.
Second seed Federer beat Philipp Kohlschreiber of Germany 6-2 7-6 to secure his place in the semis. The Swiss easily won the first set against Kohlschreiber, but he was broken twice in the match and had to save three set points in the tiebreaker after trailing 5-1 and 6-3.
He eventually reeled off five straight points to win.