Rafael Nadal rebounded from a poor start to defeat Federico Delbonis of Argentina 6-3, 6-2 on Wednesday in the second round of the VTR Open.
It was his first singles match since losing in Wimbledon more than seven months ago.
Nadal won in doubles on Tuesday with partner Juan Monaco, but the singles debut was a bigger test for the Spaniard and his injured left knee, which kept him away from the competitive game since June 28.
The seven-time French Open champion said Tuesday he's tired of answering questions about his knee and must adjust to playing with the pain. Nadal has not had surgery and is undergoing therapy and playing with a bandage.
He's acknowledged he's less than 100 percent, and his coach and uncle Toni Nadal has said doctors expect him to have to play with discomfort.