MELBOURNE, Australia — At an Australian Open flush with young talent, Marat Safin qualifies as an old-timer. He’s nearly 27, his knees have been better, and his distaste for training and practice seems as strong as ever. Even so, Safin remains a menace in the world of professional tennis, a powerfully built, racket-smashing, temper-tantrum-throwing Russian everyone in the Australian Open draw would rather avoid.

On Friday, Andy Roddick will have the honor, in only the third round. When the two last met in Australia, in the 2004 quarterfinals, they played for three hours and 20 minutes before Safin prevailed in five sets. Safin lost eventually to Roger Federer in the final, but he made good a year later, saving a match point against Federer in one of the best semifinals this tournament has ever seen, and then defeating Lleyton Hewitt in the final.

“[If] you’re asking someone who are their top six or seven favorites for this event, you know, I feel like his name is in there still,” Roddick said of Safin after a comprehensive victory over Marc Gicquel of France, 6–3, 7–6(4), 6–4, Wednesday afternoon. “If Marat is match tough, I don’t think there’s any question of his standard.”

Safin’s best has been equaled by few in the business. Not many players can run roughshod over Pete Sampras, as Safin did in the 2000 U.S. Open final. Not many defeat Federer by overpowering him, as Safin did here in 2005. Safin’s serve alone can prove the difference in a match, and his twohanded backhand bests most others.

His health and temperament are less reliable. Last February, he returned from a six-month absence after tearing a ligament in his left knee. He played poorly upon his return and dropped to no. 104 in the rankings. By the end of the year, however, he had reached a semifinal and a final, and clinched the Davis Cup for Russia in Moscow. In Australia, he is seeded no. 26.

Safin has had plenty of practice this week, perhaps too much for his own good. He needed five sets in each of his first two rounds, first against Benjamin Becker, who ended Andre Agassi’s run at the U.S. Open last year, and Wednesday against Dudi Sela, an unheralded Israeli with a wonderful one-handed backhand and lots of flair.

If not for a rain shower late in the match, Sela may have won. Safin took the first set and served for the second when Sela came alive, breaking Safin twice to even the match. For the next two sets, the underdog played beautifully, spinning lobs over the 6-foot-4 Safin, rifling backhands down the line, and dropping delicate volleys. One of Sela’s running forehand passing shots sent Safin tumbling to the court.

Sela’s luck ran out in the fourth set, with Safin serving at 5–6, 30–30. Mist became rain, and Safin asked chair umpire Sandra De Jenken to examine the court. She stopped play; 15 minutes passed as the roof closed. When the match resumed, Safin served an ace, followed by a strong serve that produced an easy forehand.

The ensuing tiebreaker was tense, but Safin won it and did not lose another game for a final score of 6–3, 5–7, 4–6, 7–6(4), 6–0 (Sela began to cramp up). Afterward, Safin admitted that without the rain, he “was lost.”

“I asked them to stop the match because it was really a little bit slippery,” he said. “I wasn’t an a——, but I used the opportunity.” Call it wisdom.

Could Safin survive another five-setter? “As many as I need to win,” he said. He and Roddick have played six times and won three apiece.

As old man Marat plods along, the tour’s youngsters are thumping one opponent after another. Four of the men who reached the third round on Wednesday are age 20 or younger (Novak Djokovic, Richard Gasquet, Gael Monfils, and American Sam Querrey). Together, they have lost three sets i eight matches. The other half of the draw contains five other young bucks who were fighting for the third round early Thursday: Andy Murray, the 19-year-old Scotsman; Tomas Berdych, the imposing 22-year-old Czech; Stanislas Wawrinka, a 21-year-old Swiss; Juan Martin Del Potro, an 18-year-old Argentine; and 19-year-old American Alex Kuznetsov (Rafael Nadal, age 20, is there too).

Djokovic, a Serb who could meet Federer in the fourth round, probably has the brightest future. He’s motivated and fit, and the least prone to stupid mistakes (he also has developed a reputation for gamesmanship). Murray’s silky game runs a close second; Gasquet is the most versatile and stylish. Querry, more comfortable as a pro by the day, has the best serve and plays as if he hasn’t a care in the world.

Monfils is the most intriguing of them all. The 20-year-old Frenchman, whose family is from the French Antilles, is by far the most gifted athlete in tennis, and he is quickly reinventing the art of “pushing” — that is, playing like a backboard. Sure, Monfils hits serves at 140 mph; in his four-set victory over a dazed Marcos Baghdatis Wednesday evening, he hit one forehand 118 mph. But he mostly runs furiously and dinks returns, relying on loopy topspin and forehand slices (his strokes are quite long and awkward). Monfils slides on hard courts as much as Nadal does on clay. When he squeaks to a stop, his trailing ankle is usually parallel to the ground.

Not surprising, Monfils has sustained several ankle and foot injuries; he also hobbled (acted?) against Baghdatis at the end of the third set, but said he was fine after he removed tape that was compressing his left foot. Jim Courier, the former French Open champion, marveled at Monfils’s talent when we spoke after the match, but said he had his concerns.

“I love watching him play, but he is abusing his body out there,” Courier said. “He’s a great athlete who happens to be playing tennis.”

Monfils is in no mood for change. He recently split with Pier Gauthier, his coach since September and a proponent of a more aggressive, and less taxing, brand of tennis. After defeating Baghdatis 7–6(5), 6–2, 2–6, 6–0, Monfils said he was confident he could sustain his habits.

“It’s natural,” he said.

tperrotta@nysun.com