World number one Rafa Nadal continued his smooth progress at the ATP event in Indian Wells on Tuesday, easing past Russian Dmitry Tursunov [Images] 6-3, 6-3 to reach the fourth round.

The Spaniard, who has won three of the past four Grand Slam titles, clinched victory in one hour, 17 minutes to set up a clash with 14th seed David Nalbandian [Images].

Champion Novak Djokovic [Images] survived a testing second set to beat German Tommy Haas [Images] 6-2, 7-6, while Juan Martin Del Potro also advanced.

Nadal took time to get into his stride against the Russian but managed to break twice to take the opening set.

Tursunov battled hard at the start of the second set to stay on terms but Nadal grabbed the break in the eighth game.

The Russian had one break point chance to stay alive but Nadal saved it and then won the next two points to book his place in the last 16.

Third seed Djokovic cruised through the first set against Haas but had to fight hard in the second before setting up a meeting with either Stanislas Wawrinka or Sam Querrey.

Former world number two Haas, who has slipped to 64th in the rankings, held two break points that would have put him ahead 5-3 in the second set but Djokovic survived and played a superb tie-break, winning it 7-1 to clinch victory.

"I had some chances to finish the match a little before I did but he stepped it up," Djokovic said.

"It got a bit intense out there -- we saw some rackets broken, on his side and mine, and a bit of swearing.

"I hope the people didn't hear that."

Sixth seed Del Potro edged out Austrian Juergen Melzer 6-2, 2-6, 7-6, but former world number one Marat Safin [Images] was beaten 6-4, 6-4 by American John Isner.

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