Open crown in frustrating cicrcumstances, bowing out with a shoulder injury during his first-round clash with Cedric Pioline.

Bermuda-based Rafter had seemed on his way to an easy victory on Tuesday night after taking the first two sets against the Frenchman, but the right shoulder that has bothered him for months got worse as the match went along.

Rafter's service speed dropped game by game despite several visits by a trainer for massage. When the match went into the fifth set and Pioline broke his serve, Rafter approached the net, shook his head sadly and gave up as numerous fans booed him.

It was the first time a defending champion -- man or woman -- had lost in the first round in the history of this Grand Slam tournament going back to 1881.

"It was a sharp pain, only on the serve,'' Rafter said, adding that he began feeling it midway through the first set. "I've been practising for the last few days, feeling great. I was very confident, very happy with the progress.

For it to break down that quickly, I was very surprised.

"For me, it's very tough to pull yourself off the court like that. I sat there (after the fourth set) and I knew I should have just walked off at that stage, but I didn't. Even if I had won that game, I couldn't see myself pulling up for the next match. But I still didn't want to walk off the court.'' Rafter said he was especially bothered by the boos after being treated so well by fans while winning back-to-back titles.

"It's very sad,'' he said of the fans' reaction. "What can I do? It is very disappointing. To be booed off, that hurts, no doubt about it.'' Pioline couldn't take too much satisfaction with this 4-6, 4-6, 6-3, 7-5, 1-0 victory.

"I played good against a great player,'' the Frenchman said. "I noticed that he began to serve with less power in the third set, but you never know whether he's going to give up. I just had to stay in there when he was playing really well, and hope that he would start missing a few.'' Rafter first started feeling the effects of the injury back in May at the Italian Open in Rome, where he reached the final only to lose to Gustavo Kuerten.

The Australian world number four was scheduled to have an MRI scan yesterday and planned to meet with doctors before deciding what treatment to undergo.

Agony: Patrick Rafter gets emergency treatment from a trainer on the injured right shoulder which forced him to bow out of the US Open during his first-round match against Cedric Pioline.