BRIEFLY : SAMPRAS' BACK INJURED AGAIN.

Byline: Daily News Wire Services

Pete Sampras' bid to finish the year as the world's No. 1 men's tennis player for a record sixth straight time suffered a setback when he withdrew from his quarterfinal match at the Lyon Grand Prix tournament in France with a back injury.

The 26-year-old said he suffered the injury in his first-round match against Todd Martin. He said it was more serious than previous back troubles he's experienced.

``It feels like the left side of my back is locked,'' Sampras said.

Sampras was to travel to Stuttgart, Germany, to see doctors before he considers playing in the Eurocard Open, which starts Monday.

Sampras' withdrawal gives world No. 2 Marcelo Rios the chance to reduce his lead in the world rankings. Rios faces Tommy Haas, who won a walkover after Sampras' withdrawal.

Meanwhile, unseeded Wayne Ferreira posted the biggest upset of the $750,000 tournament when he beat No. 2 seed Patrick Rafter 6-4, 6-1.

Andre Agassi rallied from a 0-4 deficit in the final set to beat Thomas Johansson 6-7 (6-8), 6-4, 6-4 and advance to the semifinals of the Czech Indoor ATP tournament. Agassi will face Wayne Black next.

Venus Williams and Monica Seles scored overwhelming victories in the quarterfinals of the $1 million Kremlin Cup in Moscow, taking less than two hours between them to advance.

Williams defeated Katarina Studenikova 6-1, 6-0, and Seles beat Sylvia Farina 6-0, 6-1. In the semifinals, Williams has to face Mary Pierce, who beat Spain's Magui Serna 7-5, 6-3 and Seles meets Sandrine Testud, who upset Conchita Martinez 7-6 (7-4), 7-5.

GOLF: Jay Sigel posted the second-best Senior PGA Tour score ever, a 10-under-par 61, and held a three-stroke lead after the first round of the Kaanapali Classic in Hawaii.

Dottie Pepper's round of 2-under 70 boosted her to a three-stroke lead after two rounds of the Samsung World Championship of Women's Golf in The Villages, Fla.

Pepper's two-day score of 5-under 139 put her ahead of the second-place group of Annika Sorenstam, Brandie Burton and Liselotte Neumann.

Davis Love III was among a group of six players tied at 7-under 137 after two rounds of the PGA's Disney Classic in Lake Buena Vista, Fla.

MOTOR SPORTS: Kenny Schrader, who hasn't won a Winston Cup race since June 1991, came up with his second pole in three races, taking the top qualifying spot for the Dura-Lube 500 at Phoenix International Raceway.

SOCCER: D.C. United's Marco Etcheverry, whose midfield dominance went beyond his league-leading 19 assists, was selected Major League Soccer's Most Valuable Player.