Tommy Haas, representing the brash, super-confident new generation of German players, powered into his first Grand Slam semi-final here yesterday, while just a few hours earlier his countrywoman Steffi Graf, the holder of 21 major titles but slipping into the twilight of her illustrious career, failed to reach the last four when she was crushed 7-5, 6-1 by an old foe Monica Seles.

With his reversed baseball cap seemingly never detached from his head, Haas has the tennis world at his size 12s. So far, at 20, he has yet to win a title since turning professional three years ago. His time may come this Sunday in the final of an Australian Open which has, at least on the men's side, been entirely unpredictable.

Haas's passage to the last four has been a seed-free zone. It had appeared likely he would meet Cedric Pioline, the 1997 Wimbledon finalist, in the second round, but Australia's talented teenager Lleyton Hewitt did the German a favour by dispatching the Frenchman. Haas's power then put paid to Hewitt, and he eased into the quarter-finals with the minimum of fuss and only two sets dropped. Nobody had an easier route: only one of his victims, France's Fabrice Santoro, came from the top 100.

Although his quarter-final opponent Vince Spadea was ranked 44, 11 places lower than Haas, and the German had won their one previous meeting, it was felt that the 24-year-old American's greater experience might be significant. Not a bit of it.

Haas left Hamburg as a teenager to train with Nick Bollettieri at his tennis school in Florida where, unsurprisingly, he was encouraged to belt the cover off a million balls. As yet there is no great subtlety or variety; both first and second serve are invariably pummelled, while he approaches the net with caution, relying instead on huge ground-strokes, the forehand being the bigger weapon.

Hitherto, Haas had never won more than four consecutive singles matches on the professional circuit. Indeed, neither had Spadea. One of them had to give and after a tense first set, which Haas won on the tie-break, the German's greater weight of shot saw him take relentless control. With Haas 0-40 on his own serve in the second set, and 6-5 ahead, Spadea had the chance to force a second tie-break and perhaps turn the match around, but Haas held firm to win 7-6, 7-5, 6-3 with his huge serve crucial in the third set.

Haas now plays Russia's Yevgeny Kafelnikov, the last remaining seed, who easily defeated the American Todd Martin, seeded 15 to the Russian's 10, in straight sets, 6-2, 3/5, 7-6, 6-2.

The quarter-final between Graf and Seles revived memories of their formidable tussles prior to the Seles stabbing incident in 1993, memories Seles clearly wished not to be reminded of when afterwards she brushed aside any notion that they were significant.

Her stabbing in Hamburg by Gunter Parche, a supposed fan of Graf, was obviously beyond her influence, and clearly she still feels psychologically uncomfortable with that association. Hence the cursory handshake with Graf after yesterday's win.

They met in the final here in the year of the stabbing, Seles beating Graf 4-6, 6-3, 6-2. At that time Seles had ousted Graf as the dominant force in women's tennis; thereafter the German went on to win 10 Grand Slams. Small wonder, perhaps, that Seles - four years younger at 25 - harbours ambiguous emotions.

On this occasion Graf began brilliantly, no doubt feeling that if she did not dominate the early exchanges the American might surge back. And so it proved, with Graf losing all confidence on her serve and Seles - who has never lost in Melbourne, having won the title four times in as many visits - taking full advantage of her opponent's more vulnerable sliced backhand.

Australian Open (Melbourne)

Men's Singles - Quarter-finals (prefix number denotes seeding): (10) Y Kafelnikov (Rus) bt (15) T Martin (US) 6-2 7-6 (7-1) 6-2, T Haas (Ger) bt V Spadea (US) 7-6 (7-5) 7-5 6-3.

Women's Singles - Quarter-finals: (2) M Hingis (Swi) bt (7) M Pierce (Fra) 6-3 6-4, (6) M Seles (US) bt (10) S Graf (Ger) 7-5 6-1.

Mary Pierce who was beaten 6- 3 6-4 by Martina Hingis .