A 15-year-old newcomer had defending champion Justine Henin-Hardenne on the run at the U.S. Open on Tuesday and an experienced campaigner put paid to former winner Marat Safin.

Top-seeded Henin Hardenne beat Czech qualifier Nicole Vaidisova 6-1, 6-4 but the score failed to tell the whole story of a match that almost got away from the Belgian.

Russia's Safin could not pull his game round, however, falling 7-6, 6-4, 3-6, 6-3 to Sweden's Thomas Enqvist in a tough first-round draw for the 13th seed.

It was the 2000 champion's earliest exit from the tournament for six years.

"I've not got enough confidence to beat these guys at the moment, coming to a tournament like this without any confidence is a little bit tough," a gloomy Safin said.

"To be honest I'm not feeling very happy with myself."

After breezing through the first set in 17 minutes Olympic champion Henin-Hardenne dropped 4-1 behind in the second against an opponent revelling in performing on the big stage for the first time.

Normal service was resumed when Henin-Hardenne came back to win five consecutive games but she admitted afterwards the teenager, who won her first WTA tournament in Vancouver earlier this month, had proved a big surprise.

"I started to sleep a bit at the start of the second set and she started to play better, I wasn't ready for it," said the 22-year-old Belgian, who returned from a debilitating virus to claim the gold medal in Athens.

"She was pushing me and I knew it could go to a third set if I didn't stay calm."

OUTSTANDING SEASON

Fifth seed Lindsay Davenport, who is one of the favourites to challenge Henin-Hardenne for the title, cruised into the second round with a 6-4, 6-0 defeat of Slovakia's Lubomira Kurhajcova -- her 18th consecutive victory of an outstanding hardcourt season.

Another serious contender for the title, French Open champion Anastasia Myskina, was equally impressive, crushing Ludmila Cervanova 6-1 6-0 in 42 minutes to lead a host of Russian women into the second round.

Last year's beaten men's finalist Juan Carlos Ferrero will have to improve dramatically if he is going to make a similar impact this year.

The Spaniard spent four hours, 28 minutes on Louis Armstrong Court to scramble past Czech qualifier Tomas Zib 4-6, 7-5, 7-6, 6-7, 6-3.

Fifth seed Tim Henman was also forced to dig deep against giant Croatian ace machine Ivo Karlovic.

Despite being aced 39 times the British player, who has been hampered by a lower back injury, recovered from a two sets to one deficit to win 7-6, 6-7, 4-6, 6-4, 6-4 in three hours, 37 minutes.

Double Olympic gold medallist Nicolas Massu of Chile maintained his hot streak, blasting away Jose Acasuso of Argentina for the loss of just six games.

Thailand's Paradorn Srichaphan also cruised into the second round, coming from a set down to beat Victor Hanescu of Romania 4-6, 6-4, 6-1, 6-1.

There were several seeded casualties on day two, including men's 24th seed Ivan Ljubicic who fell to Lee Hyung-taik of South Korea and Germany's Rainer Schuetttler who squandered a two-set lead against Italian Andreas Seppi.