INTERNATIONAL: Rafael Nadal toppled big-serving American Reilly Opelka 7-6(3) 7-6(5) to remain perfect on the year while unseeded Serbian Miomir Kecmanovic stunned world number six Matteo Berrettini 6-3 6-7(5) 6-4 in the fourth round of Indian Wells.

Despite Opelka's serve reaching speeds as high as 147 miles per hour, the Spaniard was the better in their rallies, dictating points and eliciting errors from the baseline.

After a high-level first set, Nadal wobbled in the second, playing a sloppy service game to go down a break at 3-2 and he tapped his head in frustration during the changeover.

But he regained his focus, breaking back to level at 4-4 and remaining perfect on serve in the second tiebreaker. He sealed the victory with a beautifully constructed point that pushed Opelka off the court.

"He is a very difficult player to play against with his huge serve and huge forehand, but I think I played my best match of the tournament so far," Nadal said in an on-court interview.

Nadal stood as far back off the baseline as the court would allow on his returns and often had to hit them at head height or higher.

"It's not only about the speed. The spin is also difficult to read. Sometimes it's coming with topspin, sometimes with slice.

"It's a great victory for me against one of the toughest opponents I can play and I'm very happy. I can't thank you enough for all the positive energy that I receive every single day here."

Nadal is now 19-0 to start the season and if he can win his fourth title in the California desert, he will move into a tie with Novak Djokovic for the most Masters 1000 titles with 37.

Rafa Nadal dug deep last night to beat mercurial wildcard Nick Kyrgios 7-6 5-7 6-4 in a blockbuster quarter-final match that lived up to the hype at Indian Wells.