Glen Johnson knocked out Roy Jones Jr. in the ninth round last night in Memphis to retain his IBF light heavyweight title and cast more doubt on the future of one of boxing's most storied fighters.

Jones lay on his back moving only slightly for almost four minutes after he was felled by an overhand right, followed by a short left. Trainers filled a towel with ice and slid it under Jones's head as he lay on the canvas, but he had trouble opening his eyes.

Jones, 35, finally walked out of the ring with help from his trainers.

The defeat left Jones's once-impressive career in tatters.

Jones turned pro after the 1988 Olympics, where it was widely perceived he was robbed of the gold medal. He has won titles at classes ranging from middleweight to heavyweight -- last March he won a piece of the heavyweight title by taking the WBA crown from John Ruiz.

Last November, he captured the light heavyweight crown from Antonio Tarver in the first of their two fights. But he was defeated by a crashing left from Tarver in their rematch.

Johnson, 41-9-2, with 28 knockouts, came out the aggressor from the opening bell last night. He threw a total of 437 punches to 270 for Jones and kept the challenger against the ropes for most of the fight.

By the seventh round, the crowd was booing and calling for more action from Jones.

The knockout came on Jones's first fight after the defeat by Tarver in May. Jones, 49-3, tried to argue then that he could continue the fight against Tarver, but there could be no such claim against Johnson.

* SOCCER: U.S. forward Clint Mathis entered as a substitute and scored late in the second half in Berlin, leading Hannover 96 to a 1-0 upset of Schalke for its first victory this season in the German league.

Mathis, a spark for the Americans during the 2002 World Cup, languished on the bench until the 81st minute. Ninety seconds later he stripped a Schalke player of the ball and beat two defenders off the dribble. He then passed and from the right side volleyed in a cross.

Afterward, Mathis ran down the sideline and tapped his watch at Coach Ewald Lienen as if to say he should have been in the game sooner.

"Naturally, he wanted to play earlier," Lienen said. "But this way he came in with the necessary anger in his belly." . . .

Defending champion Arsenal stretched its unbeaten record in the Premier League to 47, winning, 1-0, at Manchester City on a rare goal by Ashley Cole.

Cole took a deflected pass from Jose Antonio Reyes and scored with a left-footed shot in the 13th minute, his first goal in more than two years.

"He was cool like a real striker," said Arsenal Manager Arsene Wenger, whose team has beaten City the last 11 times they've played.

* TENNIS: Serena Williams overcame problems with her serve to defeat Russia's Vera Zvonareva, 6-2, 6-3, advancing to the China Open final in Beijing against U.S. Open champion Svetlana Kuznetsova.

Kuznetsova beat Wimbledon champion and Russian countrywoman Maria Sharapova, 6-2, 6-2, in the other semifinal.

* CYCLING: Defending champion Roberto Heras lost 30 seconds of his lead in the Spanish Vuelta, a day before Spain's premier cycling race ends.

The Spaniard is still in front of countryman Santiago Perez by 43 seconds entering the 17-mile time trial today in and around Madrid.

The 20th stage, a 110-mile leg, was won by Spain's Jose Gutierrez of the Phonak team. He finished by himself in 4 hours 52 minutes 20 seconds. He was 38 seconds ahead of Eladio Jimenez of the Kelme team.

-- From News Services