|Nadal's injury problems could affect his chances in the upcoming Australian Open in Melbourne [Reuters]
Defending champion Nikolay Davydenko will take on world number two Roger Federer in the Qatar Open final after dismissing an out-of-sorts Rafael Nadal 6-3 6-2.
The Spaniard - who complained of feeling unwell after just the third game - was beaten by Davydenko in a repeat of the 2010 final, which the Russian also won.
Concerns will be raised about Nadal's fitness after he struggled throughout the week.
And with just one week before the Australian Open starts, the world number one will be a clear target for those below him in the rankings.
In contrast, Federer survived a second-set onslaught from Jo-Wilfried Tsonga, who himself is working back to form.
The Frenchman took over a set to become involved in the match, his trademark power only becoming a factor later in the match.
But 16-time Grand Slam champion Federer had too much for his younger counterpart, winning 6-3 7-6.
Dip in form
Davydenko has dropped to 22nd in the world, after a dip in form which hasn't seen him reach a semi-final since Rotterdam in February 2010.
The Russian went an early break down in the first set, before storming 11 of the next 12 games.
Nadal put up little resistance, before providing something for the Doha crowd to cheer later in the second set.
But it was too little too late, as Davydenko broke for the fifth time to wrap up his sixth victory in 10 career meetings with the world number one.
But his record against Federer would suggest he will fail to defend his title in the Middle East.
The Swiss has won 14 of their 16 matches, including the last two.
And if his form against Tsonga is anything to go by, he will be closing the gap to Nadal in the rankings before the Australian Open.
Despite there only being one break throughout his semi-final match, he did not face a break point, and lost just seven points on his first serve.
Tsonga did wake up to force a second-set tie break, but Federer eased through to the final, where he will be the strong favourite.