Indian Wells, California  - Holder Novak Djokovic swept through the first set and struggled in the second before consolidating his Indian Wells Masters title defence campaign with a 6-2, 7-6 (7-1) defeat of Tommy Haas on Tuesday.

The Serbian third seed finally prevailed over the one-time number 2 from Germany - now ranked 64th - in an hour and three-quarters.

Djokovic is bidding for his second title of the season after winning a fortnight ago in Dubai but losing both of his Davis Cup rubbers against Spain.

The 21-year-old now stands 2-0 against Haas, 31 next month, who is again struggling to come back after more shoulder trouble in 2008. Djokovic won his 16th match of the season against six losses while Haas now stands 6-5.

Djokovic lost serve once while breaking Haas three times.

Women's seeds continued to advance, led by number 4 Russian Vera Zvonareva, a winner over China's Li Na 6-4, 6-4.

"It was very tight from the very beginning. I wouldn't say I was controlling everything," said Zvonareva, now 3-2 against the Chinese number 45.

"I'm very happy about the way I was able to finish up the first set and the second set. I had to serve out for the first set and serve out to close the match, and I did that well."

Eighth seed Victoria Azarenka of Belarus ended the run of Israeli Shahar Peer 7-5, 6-4 while 18-year-old Danish talent Caroline Wozniacki, seeded ninth, beat the younger of the Polish Radwanska sisters, Ursula, 7-5, 6-3.

Russian Anastasia Pavlyuchenkova, who upset second seed Jelena Jankovic in the second round last week, advanced into the quarter- finals as Spain's Nuria Llagostera Vives wilted with a left hip injury trailing 6-3, 3-0. (dpa)