Lleyton Hewitt is banking on his reputation as a tennis ironman to carry him to a second US Open title after rain turned the grand slam into a war of attrition.

Another misty day in New York had Hewitt and most of his rivals facing the draining prospect of needing to win four best-of-five-set matches in five days to claim the title.

Sixth seed Hewitt was to resume his fourth-round clash with 11th seed Paradorn Srichaphan on Wednesday after it was suspended at 10.39pm with the Thai leading 4-3 in the first set with games on serve.

The pair finally arrived on the Grandstand court at 9.18pm - 29 hours after match's scheduled start time - and traded a service break each before rain again intervened after 21 minutes.

With the crowded schedule set to take its toll, Hewitt may be advantaged with his fierce competitiveness, steely mind and supreme fitness looming as key factors in determining this year's champion.

The 22-year-old Australian is familiar with heavy workloads, having played an extremely hectic schedule for the previous three years before cutting back in 2003.

In 2001, the year he won the US Open, Hewitt played a phenomenal 98 matches in total, winning 80.

Only Roger Federer, with 230 matches, has played more than Hewitt (222) since 2001.

Hewitt also thrives in adverse situations, as seen at the 2001 Open when he overcome considerable off-court pressures and a series of tough opponents to capture his first grand slam title.

Hewitt created a furore when he questioned the umpire during his five-set second-round win over American James Blake, who later accepted the Australian's explanation that there were no racial undertones in his outburst.

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