The Spaniard, who won his ninth grand slam at last month's US Open, overpowered the 22-year-old with a polished all-round performance.

Nadal broke the 83-ranked Kazakh at 3-2 in the first set and and won six straight games before Kukushkin answered back. Nadal served well throughout the second set and kept his opponent on the back foot with some punishing forehand drives.

“It was a much better performance than yesterday and I felt really happy. My serve-kick worked really well,“ Nadal told reporters.

Referring to his US Open triumph, Nadal said he still had more room for improvement and admitted it would be difficult to keep his No. 1 ranking for a long time.

“I'm not the best tennis player yet. Winning and losing depends on how I prioritize. I just want to enjoy it and become a better player year by year,“ he added.

Unseeded Jarkko Nieminen and Benjamin Becker booked places in the semiinals after impressive runs in a tournament decimated by early exits of its top-ranked players.

Finland's Nieminen beat third-seeded Austrian Juergen Melzer 6-3 7-6 to set up a semi-final with Becker, the 2007 finalist, who outplayed fellow German Daniel Brands 6-4, 6-2.

Nieminen, the world No. 60, put his form down to a recent change in coach and improvements to a game he said had stagnated.

“We've worked on a lot of things, especially the serve, and everything takes time to take shape,“ he told reporters.

“I'm 29 now and I have been doing the same things for a long time, so it takes a while to implement changes into my game but I think I am serving better than ever now.“

Nadal and Latvian Ernests Gulbis are the only seeded players left in the competition. Those who made early exits include second-seeded Fernando Verdasco, former US Open champion Juan Martin del Potro and Serbian Viktor Troicki.
 

In Kuala Lumpur, Igor Andreev and Mikhail Youzhny will face each other in an all-Russian semifinal at the Malaysian Open after both battled through three sets in their quarterfinal matches Friday.

Qualifier Andreev, who was once ranked in the ATP Top 20, ended the dream run of Canadian teenager Milos Raonic 6-1, 3-6, 6-3.

US Open semi-finalisches against his 102-ranked compatriot, with their last meeting in January 2009 in Doha.

Youzhny earned his 37th victory of the season in two hours 40 minutes of struggle against Baghdatis, with the Russian breaking serve seven times.

Andreev put an end to a run in which Raonic won his first two career victories on the ATP.

“It was a very tough match,“ said Andreev. “He's got a lot of potential. I'm happy with how I played today, I was able to use my chances and earn the win.

“It's been a long time since I've played a semi-final (February 14 on clay in Brazil). It's great to play well again and win some matches.
 

In Tokyo, top seed Caroline Wozniacki outmuscled Victoria Azarenka of Belarus 6-2, 6-7, 6-4 to reach the final of the Pan Pacific Open on Friday.

The Dane overcame Azarenka's noisy grunting, tantrums and occasional flashes of brilliance to advance to the final of the $2 million tournament in Tokyo.

“After the first set the second was really tight,“ said Wozniacki, who is closing in on the world number one ranking. “I got the break in the third though and it was a new match.“

The Dane faces Russia's Elena Dementieva who defeated French Open champion Francesca Schiavone of Italy 6-4, 7-5 in the other semifinal.

Wozniacki stormed through the first set but was pegged back after an error-strewn second in which both players struggled to hold serve.

Normal service was resumed in the decider with Wozniacki pinning Azarenka back with some ferocious deep hitting before bringing up three match points.

The Dane was held up briefly after a successful line-call challenge from Azarenka on the first but clinically brought proceedings to a close with an ace the middle.

Wozniacki can overtake Serena Williams at the top of the world rankings by winning in Tokyo this week and following that with a quarter-final finish in Beijing next week. (Reporting by Alastair Himmer; Editing by John O'Brien; To query or comment on this story email [email protected])