INDIAN WELLS — Rafael Nadal was serving for the match at 5-4 in the second set when a funny thing happened at the BNP Paribas Open. Nadal, the world's No. 1 player, didn't close out his semifinal match against Andy Roddick.

Roddick broke back to tie the match and seize momentum.

The reason for the lapse?

“Scared maybe,” Nadal said. “I had important mistake in 30-all with the forehand. I have bad selection of the shot because I played with too much risk, yeah.”

Nadal said he had become too defensive. After the break, Nadal regained his aggressiveness to win the tiebreaker and take the match at 6-4, 7-6 (4) on Saturday at the Indian Wells Tennis Garden.

“In the second set I started to play more defensive, no?” Nadal said. “Maybe with 6-5, I started again to play a little bit more aggressive.”

Nadal had lost his serve twice in the second set, both times relinquishing control of the match. The first break came with Nadal leading 2-1 and 30-0 on his serve.

“For me, the worst game wasn't the 5-4. For me, the worst game was the 2-1, 30-0,” Nadal said. “In 5-4, you are serving for the match, and always is tough. But with 2-1, 30-0, 6-4, 2-1, 30-0, I had the match completely under control.

“Yeah, this is not the right moment to lose that game, no?”

For Roddick, he said he never felt comfortable on the court. Typically, the hard courts at the Indian Wells Tennis Garden play slower than many hardcourts with a high bounce, which works to Nadal's advantage. Saturday, the winds started kicking up, making it hard for Roddick to find a groove.

“I was going to have to execute very well. I kind of hung around and did what I could,” Roddick said. “Conditions were real tough out there. You know, his ball was — even when it landed short, it was kicking up, and then there would be the crosswind — I don't know that I felt comfortable out there today.

“Obviously with serving, you kind of have a little bit of a hesitant toss when it's gusty like that. It was tough. I mean, he just handled it better than I did.”

For Roddick, it was his third appearance in the BNP Paribas Open semifinals, but he has never reached the final.

However, Roddick said he was encouraged by the progress he has made this year, which included losing 15 pounds.

“I think with the adjustments I've made this year I think it lends itself to me playing a little bit better on slow surfaces,” Roddick said. “I beat (David) Ferrer and (Novak) Djokovic on a slow court, and I'm not sure if that would happen a year ago.”