"I feel great,"the two-time defending French Open champ Nadal said."I feel so much better than the last months right now.
"I am in the semi-finals. When this tournament started no one pulled out so the best players in the world are here."
In the women's side of the draw,Russian Svetlana Kuznetsova overcame an opening-set loss and a problematic toe to post a victory over Nicole Vaidisova in the quarter-finals.
Kuznetsova,who recently regained her career-high world No 4 ranking after a successful swing through the Middle East tournaments,defeated 17-year-old Czech Vaidisova 4-6,6-3,6-4.
"She played a good match and it was very tough out there,"said Kuznetsova,who is seeded second in Indian Wells."It was very important for me to hold my serve in the third set."
Kuznetsova,the 2004 US Open champion,also moves to the semi-finals where she will play Sybille Bammer.
At one point in Thursday's match Kuznetsova had to remove part of a broken nail on one of her right toes that had worked itself loose.
"I had the problem with my toe,"she said."My nail was pinching me so much,and I kind of gave myself credit for suffering.
"Then I just took it out at the change over which was very painful. I didn't want to call the trainer. I thought I better not stop the match. I was moving good but it was hurting me a bit."
Kuznetsova continued her mastery over world number 10 Vaidisova,winning all three of their career meetings.
This was a repeat of last year's Roland Garros semi-final and the first time they had met outside of a Grand Slam. Kuznetsova also won on the grass at Wimbledon in 2005.
Bammer of Austria defeated France's Tatiana Golovin 6-2,6-3 to reach the semi-finals.
With most of the women's top seeds either skipping this event or eliminated already,the quarter-final match between Bammer and Golovin was played in front of a sparse crowd of about 400 at the main stadium.