INDIAN WELLS, Calif. -- 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 he had no expectations in terms of results.
Nadal took a 4-1 lead in the opening set with a performance that he rated as "nothing special but OK," then lost three games in a row as Harrison pulled even. Nadal reasserted himself in the tiebreaker, racing out to a 5-1 lead, and he took control of the second set by winning five games in a row after Harrison had held serve to open the set.
"I am satisfied to be in the next round. That's the most important thing," said Nadal, seeded fifth. "Two weeks ago I didn't really know if I would be here playing. I am happy to be here. I am happy to be in the third round. Good victory for me today against a good opponent.
"I am fine. My physical performance needs to improve. My movements need to improve. Matches like this help me, for sure, no? Today, any victory is important for me. If you win, you have more chances. If you have more chances, you will compete more and you will practice more and you will be ready to put yourself in 100 per cent condition in a short period of time. If you are losing very early it's tough because you can practice a lot, but at the end it's not enough, the practice. The important thing is to compete."
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 per cent 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.
"I handled his serve pretty well and I made him hit a lot of balls," Hewitt said.
"I felt like I had more chances throughout the match. The first set could have gone either way and then I dug deep early in the second set to get up a break. That was a big momentum change."
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.
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.
Urszula Radwanska upset No. 15 seed Sloane Stephens of the U.S., 6-3, 6-4.
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.