TENNIS/US Open: It was not easy, painless or pretty, but Tim Henman found a way to succeed where his Davis Cup team-mates Greg Rusedski and Alex Bogdanovic failed by beating Ivo Karlovic 7-6, 6-7, 4-6, 6-4, 6-4 in five long, uncomfortable sets to reach the second round at Flushing Meadows.

Despite his victory, the discomfort was mostly suffered by Henman, who was troubled by pain in his lower back and, at least in the early stages until his muscles warmed up, was sometimes so stricken that he could barely crouch to receive serve.

"The last few days have been a bit painful," he said afterwards, before heading for treatment.

Earlier, Henman flinched and grimaced, resorting to dipping at the shoulders like an elderly footman, which was hardly a satisfactory stance to take when confronted by 130mph serves sent down by the 6ft 10in Karlovic.

The first set ended in a tiebreak, where Henman showed that where health fails, stealth will do just as well. He was too clever for Karlovic, dazzling him with clever flicks and sending his opponent lumbering the wrong way.

The Briton, by now moving far more fluidly and hitting with much less restriction, was edging closer to breaking the Croatian's serve in the second set and mustered two set points when returning serve at 4-5. But Karlovic's service saved him and then, in another tiebreak, Henman saw three more set-points snuffed out by thunderous deliveries. Karlovic then took his first set point to level the match.

Henman looked to be heading for a long and arduous afternoon when he lost the third set but instead the Englishman found a way to break the Karlovic serve, chiefly because his forehand, never the most reliable of weapons, began hitting targets it had been missing before. He started to thread the ball past the onrushing Croat, who could never match Henman for touch or delicacy.

Henman, whose serve did not seem unduly affected by the aching in his lower back even when other parts of his game were suffering, continued in much the same vein as he broke Karlovic in the opening game of the fifth set.

He served out after three hours and 37 difficult, sore, minutes to set up a second round match against the Frenchman, Jerome Golmard.

In contrast to Henman, who turns 30 on Monday, the 34-year-old Andre Agassi still looks sprightly, especially since the fillip he got from winning his first title of the year, the Cincinnati Masters, earlier this month.

That success, which included victories over both Andy Roddick and Lleyton Hewitt, brought him here in good heart after a trying year of scraping wins out where he could. Scratching around for victories has never been Agassi's style and he certainly did not need to do that against his compatriot Robby Ginepri in the first round, winning in straight sets, 7-6, 6-4, 6-2.

Meanwhile, a 15-year-old newcomer had defending women's champion Justine Henin-Hardenne on the run yesterday and a seasoned campaigner put paid to former men's winner Marat Safin.

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

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 pairing for the 13th seed. It was the 2000 champion's earliest exit from the tournament for six years.

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.

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 at the start of the second set and she started to play better, I wasn't ready for it," said Henin-Hardenne.