MELBOURNE (Reuters) - Rafa Nadal and Andy Murray slew a pair of giants at the Australian Open on Sunday to set up a tantalising quarter-final between two of the biggest names in men's tennis. Nadal defeated Ivo Karlovic, a 2.08 metre (6ft-10in) Croatian whose serves come down like thunderbolts, 6-4, 4-6, 6-4, 6-4. It was not the Spaniard's best performance nor a match for the traditionalists. It was more of a shootout than a slugfest. Karlovic rifled 28 aces past Nadal but the defending champion knows there are plenty of other ways to take down a giant. The world number two remained patient, took his chances when they came and is safely through to the last eight. “If he serves well, you can't do anything,” Nadal said. “You just have to keep fighting and moving your legs.” John Isner is an inch shorter than Karlovic but his serve is no less lethal. The American had fired down 81 aces in his first three matches and added 14 more against Murray. The Scotsman is one of the best returners in the game and he showed why, frustrating Isner with his ability to get the ball back in play. Unlike Karlovic, Isner does not rely just on his serve and volley and was happy to go behind the baseline and rally with Murray, another strength of the world number four. The first set went to a tiebreak but Murray ran away with the second two, winning 7-6, 6-3, 6-2. He is yet to drop a set at Melbourne Park this year and is quietly confident of beating Nadal on Tuesday. “I'm happy to have won the matches comfortably,” he said. “I know the match against Rafa is going to be difficult, but I think I can win. I just need to make sure I play my best.” Nadia Petrova has been doing some giant-killing of her own in the women's draw. The Russian slaughtered US Open champion Kim Clijsters on Friday then added the French Open champion Svetlana Kuznetsova to her list of victims on Sunday, winning 6-3, 3-6, 6-1. Kuznetsova looked tired after her previous match had finished just before 2 a.m. on Saturday but did not use that as an excuse for her poor performance.
