Nadal advances at Australian Open

Defending champion Rafael Nadal has won his fourth-round match at the Australian Open, beating Ivo Karlovic 6-4, 4-6, 6-4, 6-4 and booking a quarterfinal with Andy Murray.

Second-seeded Nadal, who beat Roger Federer in last year's final at Melbourne Park, rallied after losing the second set following a ninth-game service break to beat Karlovic, at 2.08 meters (6-foot-10), the tallest man on the ATP tour.

In the previous match on Rod Laver Arena, Murray beat American John Isner, at 2.06 meters (6-foot-9) the second-tallest man on the tour.

Nadal's win here last year was his first Grand Slam title on a hard court to go with his four French Open wins and the 2008 Wimbledon championship.