INDIAN WELLS, Calif. (AP) -- Rafael Nadal, playing on a hard court for the first time in almost a year, defeated Ryan Harrison 7-6 (3), 6-2 in a second-round match at the BNP Paribas Open on Saturday.
Nadal, a two-time champion at the Indian Wells Tennis Garden, had missed seven months because of a left knee injury and hadn't played on a hard court since March 29, 2012.
The Spanish star returned to the ATP Tour a month ago and played three tournaments on clay, winning two of those and saying his knee felt better each week.
But he said in a pre-match news conference that he had no idea how the knee would hold up under the stress of a harder surface and no expectations in terms of results.
He looked sharp early in the match with Harrison, hitting his shots crisply and moving well en route to a 4-1 lead, then played well enough the rest of the way to maintain control of the match against the 20-year-old American.
"I didn't know if I was going to be able to come two weeks ago, but I'm very happy to be here,'' Nadal said on court after the match.
Earlier, Roger Federer beat Denis Istomin of Russia 6-2, 6-3 in their second-round match.
Federer, who won his fourth title here last year, lost just four points on serve, all in the first set.
Two of those were by double faults, and he never faced a break point and won 96 percent of his first serves.
"It felt good from the start and I was able to maintain that level of play,'' Federer said. "I never thought he got into the match at all. That gives you obviously even more confidence.''
Federer was done in 58 minutes, a contrast to the 2 hours and 23 minutes it took Lleyton Hewitt to upset No. 15 seed John Isner 6-7 (6), 6-3, 6-4.
Also, the women's top seed and reigning champion Victoria Azarenka overcame a 4-1 deficit in the first set to beat two-time champion Daniela Hantuchova 6-4, 6-1.
Kevin Anderson of South Africa ousted No. 4 seed David Ferrer of Spain 3-6, 6-4, 6-3.
In other matches, Benoit Paire of France beat No. 20 Philipp Kohlschreiber, Jarkko Nieminen of Finland topped No. 28 Fernando Verdasco and Leonardo Mayer of Argentina eliminated No. 30 Mikhail Youzhny of Russia.
In other women's matches, No. 7 seed Samantha Stosur earned a 6-3, 6-4 win over American wild card Madison Keys. Jamie Hampton of Auburn, Ala., upset 20th-seeded Hsieh Su-wei of Taiwan 6-3, 6-3.
Fourth-seeded Angelique Kerber defeated Irina-Camelia Begu of Romania 6-3, 6-2, and No. 10 seed Nadia Petrova of Russia beat Stefanie Voegele of Switzerland 6-2, 6-3.