Rafael Nadal's Australian Open preparations hit a stumbling block on Thursday when he was beaten 6-4, 6-4 by Frenchman Gael Monfils in the quarter-finals of the Qatar Open.
The world number one had been hoping to get some much-needed match practice before the season's opening Grand Slam, which starts on January 19, after being injured during the final stages of the 2008 season.
However, his stay in Doha lasted only three matches after he was outclassed by Monfils, who will face American Andy Roddick in the semi-finals. Roddick beat Romania's Victor Hanescu 6-3, 6-2 earlier on Thursday.
World number two Roger Federer of Switzerland also moved into the semi-finals with a 6-2, 7-6 victory over eighth-seeded German Philipp Kohlschreiber.
The second-seeded Federer will next play Briton Andy Murray who beat Ukraine's Sergiy Stakhovsky 6-4, 6-2 in the last quarter-final.
Fifth seed Monfils secured his first win over Nadal in four attempts, mixing up his game and not allowing the Spaniard to get into a rhythm.
The pair swapped breaks in the opening set before Nadal was broken again in the 10th game to hand Monfils the opening set. The crucial moment of the second set again came in the 10th game when Monfils broke the Spaniard to clinch the match.
"I played my natural game. Rafa is Rafa but I am strong believer in the fact that I can compete hard," said a beaming Monfils.
"It was a perfect start today and I was so focused. I tried to focus on every point," he added.
Nadal said he did not play his best game and also praised Monfils.
"I didn't play my best. I had a chance in the first set but he played well," said Nadal. "He was very aggressive and he served very well.
"It is not easy in the beginning of the year. I will be in Doha for a few more days and will be training hard," he added.
Federer said he was pleased to have a testing match in the quarter-finals.
"It is nice to be tested at this stage in the tournament. I was 4-1 up in the second and I was cruising. But then suddenly he came back and the momentum swung the other way. That's tennis," said Federer.
Murray said he was confident about playing the former world number one in the last four.
"I am happy with the way I am playing now. I don't see any reason to doubt my chances in the semi-final either," the Scot said.