TENNIS/ Australian Open Championships: It has taken Lleyton Hewitt almost eight hours to win his past two matches in the Australian Open and, although he joked about going for a 10km run today before his semi-final against Andy Roddick tomorrow, it will be remarkable if the man they variously call "Rusty" and the "Rock" has much more than vapour left in his tank when he squares up to the American.

Roddick has hardly needed to break sweat to get this far, having reached the last four after his opponent Nikolay Davydenko, who beat Tim Henman in the third round, retired at 6-3, 7-5, 4-1 down when experiencing prolonged breathing difficulties in the high heat. "Not quite as dramatic as it normally is," agreed Roddick, who two years ago defeated Morocco's Younes El Aynaoui 21-19 in the fifth set of their marathon quarter-final.

Any drama this year has been at the city's blackjack tables where the American, prior to last night, was up £2,300. He has also had the satisfaction of seeing Hewitt taken to five sets by Spain's brilliant teenager Rafael Nadal in the fourth round and then by David Nalbandian of Argentina last night, the Australian winning 6-3, 6-2, 1-6, 3-6, 10-8 just before midnight.

Roddick will lose his number two spot in the world to the Australian if he is beaten. The two have met five times, with Hewitt holding a 4-1 advantage. The last time they played was in the semi-finals of the Tennis Masters Cup last November, when Roddick was humiliated in front of his home crowd and later parted company with his coach Brad Gilbert.

"Obviously that's in the back of my mind and I'm sure it's going to be in the back of his as well," said Hewitt. "It's not easy playing Andy in America. He loves the hype of playing in his home country, so I'll be trying to emulate a very similar situation. But I'm sure he's going to learn a lot from that match and he's going to come out and want revenge."

Roddick would love to turn the tables and this time it is unlikely he will be trying to force the issue at the net as he attempted in Houston.

Despite the physical battering Hewitt has incurred this week he can never be under-estimated. He has a remarkable capacity for recovery. Nevertheless he entered the Open with a right-hip flexor injury and, against Nalbandian, at the end of the fourth set, had treatment on his left thigh.

Advance Australia Fair had been sung throughout the land on Australia Day, although by 11.30 p.m. here there seemed a good chance, in tennis terms, that the country would finish on its knees, raging with bitter frustration.

Alicia Molik had gone down 9-7 in the third set of her quarter-final against Lindsay Davenport, the world number one, and it appeared Hewitt was going the same way. On this day last year Hewitt and Mark Philippoussis had lost in the fourth round, giving rise to suggestions the event be moved to avoid Australia Day. "Thank Christ I came away with a win tonight," said Hewitt.

There was a good deal of ill-feeling between Hewitt and Nalbandian, who had previously criticised the Australian's behaviour on court, especially his stentorian cries of "Come on" when an opponent has missed a shot. The two brushed shoulders at a change-over and exchanged words and after the match Nalbandian reiterated his earlier criticisms in Spanish.

Hewitt, in his early days, upset Spain's Alex Corretja, the former French Open champion, with his on-court outbursts, which were considered disrespectful. Over the years he has toned things down but he was vociferous during the Open's first week and his combative attitude splits Australian opinion.

Hewitt has to be admired for his fighting spirit. There is a good deal of hypocrisy here from a sporting public that has turned a blind eye to the way its cricket team sledges opponents. Hewitt is not guilty of that. It is 29 years since an Australian won the men's title here and Hewitt is two wins away. A few more "Come ons" will surely hurt nobody.