Martina Hingis has been trying to find the spare time since she arrived at the Australian Open to see the movie Titanic. It would perhaps now be better if she waited until after tomorrow's final before reminding herself that the unthinkable can occasionally happen to the supposed unsinkable.

Few give Spain's Conchita Martinez much of a chance in the final. If they had met during the first week, however, the expectations might have been different, for Hingis was displaying distinct signs of vulnerability.

She had finished last year, after winning the third of four Grand Slams at Flushing Meadows, on a somewhat downbeat note which was attributed to tiredness. But eyebrows were sharply raised when she lost her opening match of the year to Venus Williams in Sydney.

There is nobody in the women's game capable of out-thinking Hingis, but she can be overpowered if her fitness is a little below par, as Croatia's Iva Majoli proved in last year's French Open final.

Hingis, who was 17 last September, is at a sensitive age, and the tennis circuit, with its slavish routine and claustrophobic pressures, can unbalance the most experienced and phlegmatic competitors.

There have been small hints, whispers in the wind, that all was not exactly as it should be; Hingis appeared a touch overweight and a little irritable in Sydney, and on her arrival here there were indications that the demands of being the number one were impinging slightly on her normally equable off-court temperament.

It was hardly surprising. She had taken the tennis world by storm last year, with only a horse riding accident in the spring preventing her from achieving a clean sweep of the Slams.

However, a hard-earned third-round victory over Anna Kournikova last week, and a peerless, straight-sets quarter-final win here over Mary Pierce, who had been expected to give her trouble, repaired the ring of confidence.

"I have put a lot of pressure on myself to win here again and it's good to be living up to that expectation," she said.

She and Martinez, the number nine seed, have played each other four times: the Spaniard won the first two on her favoured clay; Hingis' victories came last year on the hard courts of Stanford and San Diego.

It now seems an age since Martinez's last win against Hingis, in the Italian Open final of 1996. Hingis, only 15 years old and still with a ponytail, had defeated a horribly wayward Steffi Graf in the quarter-finals, but then resembled a fourth former up against the gym mistress in the final. Martinez was knowingly compassionless.

The 25-year-old Spaniard, the surprise Wimbledon winner in 1994, her only previous Grand Slam final, struggled badly last year, failing to get beyond the last 16 in any Grand Slam and dropping out of the top 10.

Her passage to this final was unremarkable, until yesterday, when she defeated America's Lindsay Davenport, the second seed, 4-6, 6-3, 6-3 in a semi-final lasting nearly 2 1/2 hours. And it was not pretty.

Davenport, for whom the phrase stately as a galleon might have been penned, was playing her second successive Grand Slam semi-final and should have won it. But a litany of misses cost her the second set, and by the third her always dubious physical fitness had reduced her to a leaden-legged lumber.

Martinez is not exactly swift, and was further hampered by a groin strain which needed strapping, but mentally she was always a fraction more alert, using her heavily-sliced backhand to particularly telling effect.

"Martina is really smart and sometimes toys with you. She know exactly what shot to hit every time. But we shall see how she handles the pressure," Martinez said afterwards.

It seemed that Hingis' semi-final against Germany's Anke Huber would be over in less than an hour as Hingis raced to a 6-1, 2-0 lead, playing near perfect tennis. But Huber, who had an even worse 1996 than Martinez, has been working extremely hard on her fitness, and suddenly reeled off seven successive games. The Swiss player had opened the door just a fraction and Huber barged in.

A dark and heavy cloud passed over Hingis' bright optimism; and such was Huber's power and penetration that there appeared every chance of the German, seeded 10, winning. Crucially, she failed to nail two break points when 1-0 up in the third and simply collapsed, as she has so often in the past.

In the one men's semi-final played yesterday, Petr Korda comfortably defeated Karol Kucera, who had stunned everybody by knocking out Pete Sampras on Tuesday.

"I watched that match on TV and kept hoping nothing like that would happen to me," said Hingis. It didn't, nor it is likely to now.

A second successive Australian Open title appears a certainty tomorrow. But don't mention the Titanic.