Australian Open - - Upsets Continues As Rafael Nadal Ousted by The Hands of Windy Murray

Fifth-seeded Andy Murray upset injured defending champion Rafael Nadal and 14th-seeded Marin Cilic upended seventh-seeded Andy Roddick in Tuesday's quarterfinal action at the Australian Open.

The former U.S. Open runner-up Murray was leading the second-seeded former world No. 1 Nadal 6-3, 7-6 (7-2), 3-0 when Nadal retired with a right knee injury at Rod Laver Arena. The oft-injured Nadal missed several months of action last season because of knee and abdominal issues and was unable to defend his title at Wimbledon.

"I've known Rafa since I was 13 or 14 and he is somebody I have always looked up to," Murray said after the match. "He is my favorite player to watch because of his energy and I am gutted for him."

"I came through a few difficult moments at the start of the match, but I played well and I got my tactics right," Murray added.

Nadal called for a medical timeout during the second game of the third set to get treatment on the knee, and he called it quits shortly thereafter. He and Murray, however, managed to squeeze in some terrific tennis before the abrupt ending on Day 9.

Murray and Nadal started slugging it out in the first set, but the Spaniard doesn't overpower opponents like he used to. As recently as last year, Nadal held the Aussie Open, Wimbledon, French Open and Olympic titles.

Nadal broke Murray to grab a 2-1 lead in the first set, but the Brit then rattled off four straight games on his way to taking the stanza in relatively easy fashion.

In the second set, Nadal took a spill on the court in the 11th game, not long before a tiebreak would decide the stanza. Unfortunately for Nadal, he played a poor tiebreak and Murray was in control at that point.

The 23-year-old Nadal would call for the trainer two games later, and then it was over after the next game.

Nadal said he hurt the knee at the end of the second set.

"Was in the end of the second set in one drop," Nadal said. "And I feeled similar thing to what I had last year."

"For sure for me is little bit disappointing have the pain on the knee because I think I am very close to start winning these important matches," Nadal added. "And I think I gonna do soon."

Nadal outlasted Roger Federer in last year's Melbourne finale, which gave the Spaniard his sixth career Grand Slam singles title. The powerful Spaniard, however, hasn't won a title of any kind since May of last year.

Murray took the play to Nadal on Australia Day, as the talented Brit swatted 13 aces, compared to only one for Nadal, and notched four service breaks, compared to two for the losing Spaniard, who will no longer be No. 2 in the world when the new rankings are released next week. The Dunblane, Scotland native moved on in 2 1/2 hours and became the first Brit to reach the semis here since John Lloyd in 1977.

A British male hasn't won a Grand Slam event since Fred Perry in 1936.

The 22-year-old Murray is now 3-7 lifetime against Nadal, including 2-2 in Grand Slam play. The Brit lost to the Spaniard in the fourth round here in 2007.

Murray is seeking a trip to his first-ever Aussie Open final. He was the 2008 U.S. Open runner-up to the great Federer.

The second set of the Murray-Nadal match was delayed for about 10 minutes due to an Australia Day fireworks celebration.

Murray's semifinal opponent on Friday will be the capable Cilic, who knocked out the Wimbledon runner-up and former world No. 1 Roddick in five sets, 7-6 (7-4), 6-3, 3-6, 2-6, 6-3. Cilic will now appear in his first career Grand Slam semifinal.