ST PETERSBURG, Oct 26 (Reuters) World number four Nikolay Davydenko has been fined 2,000 dollars for not trying hard enough during his shock defeat by Croatian qualifier Marin Cilic at the St Petersburg Open yesterday.

''Nikolay Davydenko was fined 2,000 dollars for lack of best effort in his second-round match against Marin Cilic,'' the governing body for men's tennis, ATP, said in a statement today.

The top seed played near-flawless tennis in the first set against the 102nd-ranked Cilic but then started making numerous errors and committed 10 double faults in the last two sets.

He was warned by Belgian umpire Jean-Philippe Dercq in the final set for not trying hard enough.

''I double-faulted to lose a game in the third set and he gave me a warning saying I was trying to lose on purpose,'' Davydenko told reporters after the match.

''I was simply shocked to hear him say that. This is just outrageous. How does he know what I was trying to do? I was so upset with the whole thing I started crying.'' The Russian is being investigated by the ATP after his first-round match against Argentine Martin Vassallo Arguello in Poland in August attracted irregular betting patterns.

Davydenko is scheduled to take part in next week's Paris Masters, where he is defending champion.

REUTERS BJR AS1747