Davydenko was in control of his first round match, with 91 per cent of his first serves going in and breaking Dorsch six times in 13 chances [AFP]

Tommy Robredo, the second seed in the Qatar ATP tennis open, was a surprise first-round loser to Agustin Calleri of Argentina in the second day of the tournament.

Calleri, ranked 42, beat Robredo 6-4, 6-4, in the Spaniard's first ever match in Doha on Tuesday.

'Every match is winnable'

After the match Calleri said: "Maybe for you it is a surprise but not for me, because every match is winnable and I always go into each one with confidence."

However, he was realistic about his prospects for the rest of the tournament. "All of [the matches] are very difficult," he said. "Everybody can beat everybody."

Robredo said: "I had chances but that is what happens sometimes. He was better than me."

Later Nikolay Davydenko, the top seed, put in a commanding display on centre court to progress to the tournament's second round, beating Benedikt Dorsch, a German qualifier, 6-3, 6-0.

Brit Andy Murray, the third seed, was also in action, easily beating Olivier Rochus of Belgium 6-0, 6-2, although Rochus showed endeavour not reflected on the score board.

'Extra power'

Murray, 20, said: "I played my normal game just with a little extra power, fitness and confidence and that stands me in good stead."

After changing his training team in 2007, Murray was upbeat about his chances this year: "I feel more relaxed. I was very up tight last year.

"You could see that from the way I was walking round the court. It didn't look like I was enjoying it even when I was winning points."

Murray, ranked number 11 in the world, will meet German Rainer Schuettler in the second round on Wednesday.

The defeat of Robredo and fifth seed Ivo Karlovic, who surprisingly went out to qualifier Christophe Rochus, open's up Ivan Ljubicic's side of the draw. Ljubicic went through to the second round on Monday.

The tournament runs until January 6 and offers a $1 million jackpot for the champion.