MELBOURNE, Australia — Another victory, this time against one of his oldest friends, and Andy Roddick returns to the semifinals of the Australian Open for the third time. Roger Federer will be waiting.

On Tuesday in Melbourne, Roddick and Mardy Fish, the lone surprise in a men’s draw that sent 14 of the top 16 seeds into the fourth round (first time in Australia since 1971) will face each other for the sixth time as pros and umpteenth time since their days in high school together in Florida, where Fish used to live with Roddick’s family. For two boyhood pals, it’s a dream meeting, especially for Fish, who’s recovered nicely from two wrist surgeries to reach his first major quarterfinal under the tutelage of Todd Martin and Scott Humphries.

Roddick will be the favorite, but if he wins, can he possibly take down Federer?

Most of you have answered “no” and considered moving on to another column in these pages. Indeed, Roddick — like everyone else in the draw — has little chance against the world no. 1. Federer’s form was suspect (for him) in the first round, and he lost to Roddick in an exhibition before the Australian Open began. So far this tournament, he has not been at his best — he has a case of the sniffles and has lost his serve eight times, one more than he did at the entire U.S. Open last year. But with each round he seems to improve; on Sunday evening he dismissed Novak Djokovic, the 19-year-old Serbian talent who still talks a bigger game than he can play, in straight sets, 6–2, 7–5, 6–3.

Roddick has faced two difficult opponents in a row (Marat Safin and Mario Ancic) and made his new coach, Jimmy Connors, proud both times (Connors missed much of the first week owing to the death of his mother Gloria). Roddick’s brother John, who also acts as a coach, is feeling positive, too.

“Last year we were worried about putting balls in the court,” John Roddick said of his younger brother. “Now we’re worried about doing damage to those balls.” Roddick seems a half step quicker than he was in years past, and it’s clear that he practices his volleys more often. Asked how much he used to practice them, John Roddick said, “I don’t even want to say.”

Patrick McEnroe, the U.S. Davis Cup captain, complimented Roddick’s attitude at the net, more so than his technique.

“He comes in like he means it,” McEnroe said after Roddick defeated Safin in four sets. “It’s almost like he is excited about going up there.”

Confidence is perhaps the most important stroke in tennis, and Roddick clearly has more of it now than he has had in quite some time. He reached the final of the U.S. Open, and held three match points against Federer in the round-robin portion of the Masters Cup. The exhibition victory over Federer counts for something. As John Roddick put it, “Neither one of them wanted to lose it.”

The Australian Open meticulously tracks the performance of its players, and the data it collects offer good news for Roddick. During last year’s U.S. Open, Roddick hit 16 winners with his backhand, his weaker stroke and until recently thoroughly predictable (crosscourt, every time). Through four matches this tournament, he’s equaled that figure. He’s hit almost as many forehand winners, too (47 so far compared to 55 through the whole U.S. Open, where the courts are slightly faster). He continues to serve at a remarkable clip: 68% of first serves in, and a 71.6% cumulative winning percentage on all — first and second — serve points.

“Either me, or Jimmy, or whoever it is would be an absolute moron to tell him anything on the serve,” John Roddick said.

What if someone said, “Get the first one in 80% of the time?” Against Federer, that might do the trick.

I write as if Federer is assured a spot in the semifinals, but by no means do I intend to slight Tommy Robredo, Federer’s next opponent and a man who has recently taken far more punishment in the press than he deserves.

One can only wonder if the abuse Robredo receives has something to do with the way he looks. By today’s standards, Robredo is skinny (5-foot-11, 165 pounds), and his bandana and haircut scream 1975 (think Luke Wilson in “The Royal Tenenbaums”). Most men on tour wear wrist bands or hip Lance Armstrong bracelets; Robredo wears a watch (and a big one at that).

During the Masters Cup, Goran Ivanisevic said Robredo was undeserving of a place among the eight best players in the world, and suggested his appearance there was evidence of weakness in tennis. This is nonsense. Robredo is just 24, and has reached the quarterfinals at the French Open twice; this is the first time he has done so in Australia. He’s a finely trained professional with a pretty one-handed backhand and exceptional technique on all strokes (yes, this Spaniard can hit a volley if he needs to). In his fourth round match against Richard Gasquet, a great talent who looked superb in his previous match, Robredo smacked 51 winners and made only 29 errors. He more than doubled Gasquet in groundstroke winners, 35 to 17. Robredo probably won’t beat Federer (he’s lost all six of their meetings), but perhaps he’ll play well enough to rehabilitate himself.

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While the men’s draw has offered few surprises, the women’s draw has been unusually volatile. Amelie Mauresmo, the defending champion and no. 2 seed, is gone, thanks to Czech teen Lucie Safarova, and Serena Williams continues to defy the odds and miss fewer shots by the day.

On Tuesday, Williams will face Shahar Peer, the 19-year-old Israeli who reached her first major quarterfinal with an upset of Svetlana Kuznetsova. It will be the biggest match of Peer’s career. If she is to win it, she’ll have to rely on her fitness and determination, and hope that her weak serve can withstand Williams’s firepower. Against Jelena Jankovic, Williams was doubled over and panting after winning the point of the match, an 18-stroke rally that ended when Jankovic, suddenly timid, bailed out on a backhand and pushed it into the net. Peer’s only chance is to play lots of points like this, and win most of them. Either way, she’ll move inside the top 15 for the first time after the tournament ends.

tperrotta@nysun.com