Facing a six-month recovery after tearing a ligament in his right knee, WBC heavyweight champion Vitali Klitschko came to a tough realization: It was time to retire.

"Unfortunately, I've been fighting injuries recently more than facing rivals in the ring," Klitschko said. "The decision to end was hard to make. But I would like to end my career on top and with my retirement make the way free for my successor."

Klitschko, 34, pulled out of Saturday's title defense against Hasim Rahman in Las Vegas because he hurt his knee last week in training. The WBC said this week that Rahman would be given Klitschko's title should the Ukrainian fail to defend it within three months.

* BASEBALL: Free agent relief pitcher Ugueth Urbina was formally charged with attempted murder and will remain in a Venezuelan prison while he is tried, his lawyer said.

Urbina, who most recently pitched for the Philadelphia Phillies before becoming a free agent, was taken to a detention center in Los Teques, just west of Caracas, the capital. He did not speak to reporters.

The 31-year-old right-hander is accused of joining a group of men in attacking and injuring five workers with machetes and pouring gasoline on them last month.

Urbina, who voluntarily came to the police to provide testimony before he was arrested Monday, has insisted he had nothing to do with the violence at his family's ranch about 25 miles south of Caracas on Oct. 16.

* COLLEGE SOCCER: Jason Garey scored the go-ahead goal in the 65th minute as top-seeded Maryland defeated Wake Forest, 2-1, to advance to the ACC semifinals in Cary, N.C. Stephen King had a goal and an assist for the No. 1-ranked Terrapins (15-3-1), who will next face fifth-seeded Duke, a 2-0 winner over fourth seed Virginia Tech (10-5-4). Second-seeded Virginia (12-4-2) was upset, 4-1, by No. 7 Clemson, which will play No. 6 North Carolina tomorrow.

* TENNIS: Mary Pierce won her 500th career match, defeating Elena Dementieva of Russia, 6-2, 6-3, at the WTA Championships in Los Angeles. Pierce improved to 2-0 in round-robin play, including her three-set upset of Kim Clijsters on opening night.

* AUTO RACING: Four-time Indianapolis 500 winner Al Unser, 66, was resting and expected to make a full recovery after doctors in Colorado removed a tumor from his liver. "He's good for another 100,000 miles," joked Unser's wife, Susan.

-- From News Services

and Staff Reports