The top-ranked Rafael Nadal advanced to the second round of the Qatar Open, beating Karol Beck 6-3, 6-0 in Doha last night.
"It was not an easy match," the Spaniard said. "I started well and then kept playing well. I think I gave a good performance."
Nadal led 3-0 in the first set, and then broke Beck all three times in the second.
"I try to do better every day and be consistent," said Nadal, who won the French Open, Wimbledon and the US Open last year. "I wanted to do that. It is important to do that to keep my [top] ranking. I am happy with the way I played."
Nadal, who is seeking his first trophy in Doha, will face either Lukas Lacko of Slovakia and Pere Riba of Spain in the next round.
Roger Federer, the world No 2, added to his repertoire of through-the-legs winners on his way to beating Thomas Schoorel, the Dutch qualifier, 7-6, 6-3.
He will play Marco Chiudinelli, a Swiss compatriot, next.
Meanwhile, Samantha Stosur, the top seed, crashed out of the Brisbane International yesterday as she was beaten in straight sets by Jarmila Groth in a second-round clash between Australia's top two players.
Stosur was outplayed as she lost the first set 6-2, but appeared to be rallying in the second. Groth would not be beaten, however, and held firm for a 6-2, 6-4 win.
Things went no better for second seed Shahar Peer, who crashed out to Lucie Safarova in three sets.
Peer seemed to be cruising through when she won the first set, but her Czech opponent, champion in 2006, rallied for a 3-6, 6-1, 7-5 win.
Men's top seed Robin Soderling experienced none of the problems of his female counterpart as he progressed to the last 16. He beat American Ryan Harrison 6-2, 6-4 to book a clash with Michael Berrer.
In New Zealand, defending champion Yanina Wickmayer battled her way into the second round of the ASB Classic in Auckland by beating former world No 1 Dinara Safina 6-3, 6-7, 6-1.
The Belgian second seed was not at her best, but took advantage of some erratic moments from Safina, who suffered badly with injuries last season.
Justine Henin continued her winning return to competitive tennis at the Hopman Cup. The Belgian, also a former world No 1, was playing her first tournament since Wimbledon last year due to an elbow injury.
She followed up her win over Alicia Molik on Saturday with a straight-sets victory over Kazakhstan's Sesil Karatantcheva.
Ruben Bemelmans settled the clash with a 6-4, 6-4 defeat of Andrey Golubev.
Henin and Bemelmans then combined to complete a clean sweep with a 4-6, 6-2, 7-6 win over Karatantcheva and Golubev in the mixed doubles.
Novak Djokovic and Ana Ivanovic maintained the buoyant mood in Serbian tennis when they overpowered Australia 3-0 to move closer to a place in the final of the Hopman Cup mixed team event yesterday.