The United States kept its spot in the top tier of the Davis Cup yesterday when Andy Roddick capitalized on his booming serve and a disputed call in the fifth set to defeat Olivier Rochus and give the Americans an unbeatable lead against Belgium.

Roddick won, 6-7 (7-4), 7-6 (7-4), 7-6 (7-5), 4-6, 6-3, in 41/2 hours to put the U.S. ahead 3-1 in the best-of-five playoff in Leuven, Belgium. The Belgians were relegated to zonal competition next year. In the final match, James Blake beat Steve Darcis, 7-5, 6-1, to make the final score 4-1.

It was the second victory this weekend for the No. 3-ranked Roddick, who was coming off a first-round exit at the U.S. Open. He served 35 aces on the red clay of the Sportplaza to undo the tireless running and creative shot-making of the 31st-ranked Belgian. Rochus was playing his third match in three days.

"Luckily, I had some great serves when I needed to," said Roddick, who had cramps during the last hour.

The Americans, behind twins Bob and Mike Bryan, won doubles Saturday for a 2-1 lead and were trying to avoid relegation from the World Group for the first time in 17 years.

The U.S., which has won 31 Davis Cup titles, is out of contention this year. Slovakia and Croatia won their semifinals yesterday to advance to the final Dec. 2-4. Both nations will be going for their first Davis Cup title.

Slovakia, playing at home, beat Argentina, 4-1, behind a clinching victory by Dominik Hrbaty. Croatia was at home and downed Russia, 3-2, with the decisive win by Ivan Ljubicic.

The match turned Roddick's way in the fifth set when Rochus missed the easiest of volleys to give the American a 4-2 lead. Officials could not find the impact mark and went with the lineswoman's call. The Belgians disputed but finally relented.

"I have never been so disappointed," Rochus said. "It could have gone either way. It was that close."

The match was the longest for the United States in 16 years and kept the capacity crowd of 3,500 spellbound.

"The crowd was going crazy," Roddick said.

With fans jeering every U.S. point after the crucial line call, the Americans left the court without celebrating.

"It would have been unprofessional," Roddick said. "You don't want that quality of a match to end like that. You would not want to rub it in people's faces."

* PGA TOUR: Robert Gamez snapped a PGA Tour-record 151/2-year stretch between wins, closing with a 6-under 64 for a three-stroke victory at the Texas Open in San Antonio.

The 37-year-old Gamez won for the first time in 394 events, a stretch of 15 years and six months. He recently surpassed Butch Baird's record of 15 years, 5 months and 10 days between wins. He also avoided Ed Fiori's mark of 409 events without a victory.

"It has been a long time, a long time coming," Gamez said. "I knew it would happen. I just didn't know when."

Gamez opened with three straight birdies and added three more on the back nine to reach 18-under 262 at LaCantera Golf Club's Resort Course.

Olin Browne also shot a 64 and finished at 15 under. Mark Wilson (68) and third-round leader Woody Austin (69) tied for third at 14 under.

The victory was worth $630,000 for Gamez, who won the Tucson Open and Nestle Invitational in 1990 and has eight second-place finishes since.

-- From News Services