A tennis feast! - Day 7

Marin Cilic and Juan Martin Del Potro put on a monumental show of big hitting in this fourth round match in which the scoreline swung back and forth throughout. I am absolutely delighted and relieved to tell you that the beast Del Potro was beaten, Cilic winning this marathon, 5-7, 6-4, 7-5, 5-7, 6-3. Del Potro was a huge threat to Federer should he have reached the final.

Current Australian Open champion Rafael Nadal faced off against giant-serving Croat Ivo Karlovic in a close encounter. Nadal took the opener only for Karlovic to level in the next set. But nadal began reading the Croat's serve and was totally on top by the fourth set. He won 6-4, 4-6, 6-4, 6-4.

Nadia Petrova continued her giant-killing act as she powered past 3rd seed Svetlana Kuznetsova in three sets, the final score reading 6-3, 3-6, 6-1.

Belgian maestro Justine Henin came up against young compatriot Yanina Wickmayer. The youngster had been the surprise package of last year's US Open, and after losing a first set tiebreak, she went on to race through the second set 6-1. But Henin, seven times Grand Slam champion, kept her cool and put on another great exhibition of her skills, winning the decider 6-3 to set up a quarter final with Petrova. As much as Henin insists it is a great physical challenge for her after missing the last couple of years on tour, she nevertheless looks like she's never been away.

In the first match of the day, Andy Murray quite comfortably beat an inept John Isner in three straight sets. While the American has a serve to boast of, he possesses absolutely nothing else based on this performance, and was rather incapable of maintaining, let alone winning, a rally. Where does this leave Andy Murray? He has had four simple matches in which he hasn't been stretched in the least, and now he must be prepared to take on the second best player on the planet in Rafael Nadal. I think we will be seeing the Scot on a plane out of Melbourne in the very near future, perhaps on Tuesday.