Nadal, Djokovic heading for semi-final showdown

Top-seeded Nadal triumphed 6-3, 6-3 in a tricky encounter with Russian Dmitry Tursunov, while third seeded Serbian Djokovic beat German veteran Tommy Haas 6-2, 7-6 (7/1).

“It wasn’t one of my best matches, true. It was tough to play against him,” said Australian Open champion Nadal, who had to save a break point in the final game but won the next three points to secure the win.

“He didn’t give me a lot of rhythm. He played good shots, but at the same time made mistakes. I had more mistakes than usual.”

Nadal had little time to savor the victory, which earned him a fourth round match on Wednesday night against Argentina’s David Nalbandian, who hasn’t dropped a set against Nadal in two career meetings, both in 2007 before the Spaniard’s rise to number one.

“The first thing is to play well,” Nadal said of what he’ll have to do against Nalbandian, who beat Serbian Viktor Troicki 6-4, 6-2.

“Second, I have to play really aggressive, because if he has control of the point it is nearly impossible.”

Djokovic, who beat Nadal in last year’s semi-finals en route to the title, started strong but would have preferred to finish off Haas more quickly.

Overall, however, the 21-year-old was satisfied that he was moving in the right direction.

“Better than the first match,” was his assessment. “I played really well in the opening set, and then could have done the job a bit earlier. I had some break chances and didn’t make a couple returns, and gave him a chance to come back into the match.”

Djokovic next plays Switzerland’s Stanislas Waurika, who saved two match points in the third-set tiebreaker to claim a 2-6, 7-5, 7-6 (10/8) victory over American Sam Querrey.

Sixth-seeded Argentinean Juan Martin Del Potro advanced, beating Austrian Jorgen Melzer 6-2, 2-6, 7-6 (7/2).

Seventh-seeded American Andy Roddick edged Germany’s Nicolas Kiefer 6-4, 7-6 (7/4).

Roddick will face 12th-seeded Spaniard David Ferrer, who rallied for a 3-6, 6-4, 6-4 victory over unseeded Frenchman Jeremy Chardy while del Potro will face American wildcard John Isner, a 6-4, 6-4 winner over former world number one Marat Safin of Russia.

Meanwhile Safin’s younger sister, top-seeded Dinara Safina, led the way into the women’s quarter-finals with a 7-5, 6-4 victory over US veteran Jill Craybas.

Safina, who can seize the world number one ranking from the absent Serena Williams if she reaches the final, lined up a meeting with eighth seeded Victoria Azarenka of Belarus, who downed Israeli Shahar Peer 7-5, 6-4.

Safina won all three of her meetings against Azarenka last year.

Defending champion Ana Ivanovic booked a quarter-final berth, the fifth-seeded Serbian downing Italian Flavia Pennetta 6-4, 4-6, 6-4. She’ll face Austrian Sybille Bammer, a 6-3, 6-2 winner over Slovakia’s Daniela Hantuchova.

Rising Russian Anastasia Pavlyuchenkova, 17, continued the run of success that saw her oust second seeded Jelena Jankovic in the second round, advancing to the quarterfinals when opponent Nuria Llagostera Vives retired in the second round with left hip strain.