The cavalry never arrived at Longwood Cricket Club today.

The United States tried mightily to send in Pete Sampras to salvage its chances in this afternoon's Davis Cup matches against Australia, attempting to insert him for Todd Martin, who said he was too ill to play. But when the tournament doctor refused to send Martin to sick bay with what Martin said was heat exhaustion, Sampras was confined to the bench, only able to watch as Martin fell to Patrick Rafter, 4-6, 5-7, 6-3, 6-2, 6-4, in the tie's decisive match.

Lleyton Hewitt then won the final match in the best-of-five quarterfinal over Alex O'Brien, 7-5, 6-4, giving the Australians a 4-1 overall victory and a semifinal pairing with Russia, which defeated Slovakia today. Much of the day's earlier controversy faded as Rafter's teammates carried him around the court, but concerns of shaky ethics dogged the U.S. team long after the spectators left.

"I think it was a very unfair situation," Australian captain John Newcombe said, noting that Rafter did not know who he would play until 20 minutes before his match. When asked whether he thought Martin was truly ill, Newcombe said, "I don't know. He played three-and-a-half hours of pretty good tennis in the heat and had Pat two-sets-to-love down and down two breaks in the fifth. I think that speaks for itself."

Martin's health has been a major topic of discussion all weekend. U.S. captain Tom Gullikson first sparked controversy Saturday when he suggested that Martin might be too ill to play today and that Sampras might take his place. Davis Cup rules forbid substitutions at such a point, except in the case of injury or illness. Gullikson denied that the possible substitution had anything to do with the fact that Sampras, considered the world's best player, might have been able to dig the United States out from its 2-1 deficit. But suspicion swirled later in the day when Martin said he felt "fine."

Today Martin said he told Gullikson he was upset that Gullikson suggested he was ill.

"I was disappointed," said Martin, who is well-respected on the ATP Tour as an honest player. "I was upset -- I wanted to play. I didn't feel like I was in bad enough [shape] not to play."

But Martin said things changed this morning when he began warming up with Jim Courier and the on-court temperatures reached 130 degrees. He said he left the court feeling weak and dizzy, and the U.S. team doctor certified that Martin was suffering from heat exhaustion. Sampras was called in from his hotel and began warming up.

But the neutral doctor who is required to approve the substitution, Richard Paul, refused to declare Martin unfit to play. Paul, an American, is a member of the Longwood Cricket Club.

"I think in this case Todd wasn't feeling well -- I think that was honest," said Stefan Fransson, the tournament referee. "But him being unfit to play, that is a different situation."

Martin was given intravenous fluids and sent onto the court. He looked pale, even to Rafter, but still managed to charge through the first two sets, taking control of the match. While he faltered in the third and fourth, he went up a break twice in the fifth before eventually succumbing to Rafter in 3 hours 14 minutes.

"Going in, I didn't feel like I was fit to play," Martin said. "When I was actually out there, I obviously was fit to play, but I also felt like I was putting myself at a fair bit of risk.

"I was actually very distracted, and I had a tough time controlling my emotions. My mother is here. I don't think she was very pleased to see me in the state I was. But that I was more distracted probably just helped me. I just went out and reacted to the ball."

Martin looked sure-footed through the beginning of the match, starting the first set by taking a 4-0 lead. He won the second set as well but gave Rafter an opening at the start of the third when he failed to convert on double-break point. Rafter used the momentum swing to charge through the next two sets, evening the match, and he appeared ready to quickly sew up the fifth.

That was when Martin, who had tightened up with the lead, relaxed again. He broke Rafter to go up, 3-0. When Rafter broke back, Martin answered with another break, going up 4-2. But that was apparently all he had to give. Rafter won the next four games, finishing the match with a serve Martin could not return.

"After the beginning of the third set, I knew I couldn't really afford to mess up anymore," said Rafter, who has won his last 11 five-set matches. "I knew if I could hold my serve, there were going to be enough opportunities to try and break him. Even down three-love [in the fifth], I still felt pretty optimistic."

CAPTION: It's a wrap: U.S.'s Todd Martin is covered with towel after five-set loss to Australia's Patrick Rafter.