Novak Djokovic of Serbia celebrates winning a point against Kevin Anderson of South Africa during their men's singles match at the Indian Wells WTA tennis tournament in Indian Wells, California March 12, 2012.  [Photo\Agencies]

INDIAN WELLS, California - World number one Novak Djokovic blunted the power serving of South African Kevin Anderson to reach the fourth round of the Indian Wells ATP tournament with a 6-2 6-3 victory on Monday.

The top-seeded Serb, who beat Spaniard Rafa Nadal in last year's final at Indian Wells, broke his towering opponent twice in a marathon opening set and once in the second to triumph in one hour 37 minutes.

"It was a very close match," Djokovic said in a courtside interview after breaking Anderson in the sixth and eight games to win the opening set in just under an hour.

"The scoreline does not reflect how close it was, especially the style of the match. In most of our matches ... the first set goes on for half an hour or more. I was fortunate to hold that break and I returned well today."

Djokovic, who lost to Anderson when they first met at the 2008 Masters Series event in Miami but won their next three encounters without losing a set, had five aces on Monday while the six-foot eight-inch Anderson delivered seven but the South African won only 41 percent of his second serves.

"This is one of my most successful tournaments," added the Serb, who was champion here in 2008 and again last year. "I love coming back to the desert."

Djokovic will next meet Pablo Andujar who advanced with a 7-6 6-4 win against fellow Spaniard Albert Ramos.

In other matches, big-serving John Isner powered past Argentina's Juan Monaco 7-5 7-5 and France's Gilles Simon beat Swiss Stanislas Wawrinka 6-4 6-4.

Seventh-seeded Czech Tomas Berdych was scheduled to play American former world number one Andy Roddick later on Monday.