INDIAN WELLS — Roger Federer was immune to losing streaks for years as the unshakable force in men's tennis.

But then Rafael Nadal unsettled his foundation. The Spaniard has defeated him five consecutive times, and, in August, he took over the No. 1 ranking that Federer had owned since February 2004.

Now another young, burgeoning tennis star is frustrating the former king.

Andy Murray defeated Federer 6-3, 4-6, 6-1 in the semifinals of the BNP Paribas Open on Saturday, taking his fourth consecutive match in six months against the 27-year-old Federer.

“I don't think I did anything incredible,” Murray said, “but that wasn't what I was trying to do when I went in to play the match.”

Steady and consistent, Murray won the deciding set, like he did in his last three victories over Federer.

For a moment, it seemed Murray might be in trouble. With Federer serving down 2-1 in the third set, the 21-year-old Scot fell down while chasing a Federer forehand. Shrieking in pain, Murray clutched his left groin, which he had torn when he was younger. But Murray recovered.

“Once I got up and ran around after a couple points, I knew that it felt OK,” Murray said.

Murray ran away with the match after the scare, winning 11 of the next 13 points while breaking Federer twice.

“He played unbelievable in the end,” Federer said. “I made many mistakes.”

Getting broken twice in the first set, Federer fought back in the second. He charged the net more frequently, and Murray was more erratic.

But that momentary rhythm escaped Federer for the remainder of the match. Federer had 32 winners, but he had the same number of unforced errors. Murray had 15 errors, three in the third set.

Struggling especially with his backhand, Federer had 18 errors on that side. With Murray persistently pressing him there, Federer abandoned his backhand, stepping around to play forehands instead.

After the match, Federer found himself explaining why he couldn't beat another opponent.

“He's a great counter puncher and reads the game very well. He's got great feel, so he's very confident at the moment,” Federer said.

Murray embraces the philosophy of retired major league baseball pitcher Greg Maddux, who didn't try to overpower hitters with fastballs, but varied the speed and location of his pitches.

“It's not just going for big, booming serves all the time and huge forehands,” Murray said. “If (I) change the pace with the ball a lot and mix it up, I'm playing the match how I want it to go.”