Davydenko wins smoothly, Robredo with difficulty

SOPOT, Poland, Aug 1 (Reuters) Austrian Stefan Koubek made a remarkable recovery to upset fifth seeded Argentine Agustin Calleri 0-6 7-6 7-5 in the Polish Open at Sopot.

Koubek lost the first 10 games, was 5-1 down in the second set, 5-2 down in the third and saved four match points before taking the first round match. He will meet Belgian Kristof Vliegen next.

Another Argentine to suffer an upset was third seed Juan Ignacio Chela, ranked 20th, who lost 6-1 6-2 to compatriot Sergio Roitman. It was Chela's second consecutive loss to Roitman after a three-set defeat at Kitzbuehel last week.

Top seeded Russian Nikolay Davydenko, the world number four and Sopot title holder, overwhelmed Romanian veteran Andrei Pavel 6-3 6-4 and will meet Argentine Martin Vasallo Arguello in the second round on Wednesday.

Number two seed Tommy Robredo of Spain, ranked seventh, had to work hard to overcome Pole Lukasz Kubot, taking more than two hours for a 6-4 5-7 7-5 victory after a rain interruption in the third set.

Robredo served for the match at 5-3 in the second set but lost four games in a row. He then led 5-2 in the decider but allowed his opponent to come back to 5-5.

The Spaniard will next meet Belgian Steve Darcis who defeated Nicolas Massu of Chile 6-7 7-6 6-4.

German Florian Mayer, runner-up to Davydenko last year, beat Argentine Juan Pablo Brzezicki 6-3 6-3 and will now meet French qualifier Olivier Patience, who overcame hard-serving Polish wild card Dawid Olejniczak 7-6 6-4.

''The match was not very easy. I had a very good start but then I failed to serve well,'' Patience told reporters. ''After winning the tiebreak I focused on my serve.'' Reuters SAM VP0505