DUBAI (AFP) - Nikolay Davydenko, the Russian who has to play with the constant uncertainty of an investigation hanging over him, earned himself a great chance of reaching only his second ATP Tour final for 17 months on Thursday.

The world number five from Moscow overcame Andy Murray, the giantkiller from Britain, 7-5, 6-4, to become an unexpected semi-finalist at the Dubai Open.

Davydenko mixed consistency with aggression with superb attacks from the baseline against an opponent who had eliminated world number one Roger Federer in the first round.

His continued excellence is all the more surprising considering that he still has no knowledge of how much longer the ATP Tour will need to check for evidence of whether or not he has had involvement in corrupt betting practices.

"I think maybe it will finish this year," he said satirically, and when there was no response, added: "Or maybe when I have finished tennis."

Davydenko won because his aggression was more effective than Murray's preference for containment and defence and occasional counter-attack, although much might have been different had the 20-year-old Scot taken his chances.

Murray had break points in both of Davydenko's first two service games, and two more in the sixth game of the second set.

"I was disappointed with that aspect of my game," said Murray, "But at least I was hitting the ball better than yesterday," he added, referring to his wind-affected contest with Fernando Verdasco.

Murray also attacked brilliantly to reach 3-0 in the second set, but was unable to capitalise on that advantage either, settling back into a more containing mode again.

"He started the second set so fast it really surprised me, so I started to play faster myself," said Davydenko.

He now plays Feliciano Lopez, the Spaniard who played superbly to reach the final here four years ago but who has won only one match since October.

Lopez, who has sunk to 41 in the world rankings, upset his compatriot, the fourth-seeded David Ferrer, 6-4, 6-3, clearly enjoying the fast hard court conditions and warm weather.

It was a victory for a player who played a better all-court game over a player with tremendous speed, brilliant forehand and tenacious back-court rallying.

Ferrer made the first break and reached 4-2, before Lopez pummelled some heavy forehands to break back and got on a roll.

He managed another break immediately, as Ferrer serve to try to save the set, and after converting his third set point, sprinted with extravagant speed to his chair.

This revealed how much success meant to Lopez, and he continued to play well in the second set.

Once again though Ferrer made the first break, but Lopez broke back with a fine pass as the world number tried to press more.

This reduced Ferrer's consistency a little, and as Lopez gradually began to feel that he was actually the favourite to win he began to play even better.

"I would like to play Igor Andreev," he announced afterwards. "But it might be Novak Djokovic."

But those two players are in the other half, and Lopez was surprised to learn that his opponent might be Murray or Davydenko.

Lopez had looked no further than the quarter-final. This was a man who surprised himself.