Roundup

LPGA MICHELOB ULTRA OPEN: : Lindsey Wright shot a 7-under 64 and Cristie Kerr had a 66 to share the third-round lead in Williamsburg, Va.

Mayfield suspended; Martin wins race

et cetera

Jeremy Mayfield was suspended indefinitely by NASCAR for failing a random drug test, becoming the first driver to violate a toughened new policy that went into effect this season. Mayfield tested positive for a banned substance last weekend at Richmond (Va.) International Raceway. "In my case, I believe that the combination of a prescribed medicine and an over the counter medicine reacted together and resulted in a positive drug test," he said in a statement. "My doctor and I are working with both Dr. [David] Black and NASCAR to resolve this matter." Black is the CEO of Aegis Sciences Corp. in Nashville, Tenn., which runs NASCAR's testing program. NASCAR spokesman Jim Hunter would not reveal what banned substance Mayfield used, but Hunter said it was not an alcohol-related offense. "There is no place for substance abuse in our sport," Hunter said.

MORE NASCAR: : Mark Martin, 50, won for the second time in four races, outlasting Jimmie Johnson in the wreck-filled Southern 500 at Darlington (S.C.) Raceway. Martin's only other victory at Darlington came at the 1993 Southern 500.

MORE AUTOS: : Helio Castroneves, back in racing less than a month after being acquitted of charges of tax evasion, took a big gamble, voiding a fast qualifying effort from earlier in the day and knocked Penske Racing teammate Ryan Briscoe off the Indianapolis 500 pole. Castroneves' four-lap average of 224.864 mph on the historic 2.5-mile oval came with less than two hours remaining in the six-hour opening round of time trials for the May 24 race.

BASEBALL: : The Cubs placed third baseman Aramis Ramirez, hitting .364 with four homers, on the 15-day disabled list with a dislocated left shoulder. ... The Yankees purchased the contract of right-hander Brett Tomko, 36, from Triple-A. New York optioned right-hander Dave Robertson to Triple-A. ... The Athletics added infielder Adam Kennedy to the roster one day after acquiring him from the Rays. ... Mets manager Jerry Manuel was suspended one game and fined for making contact with an umpire during an argument Thursday night. ... The Mariners placed Carlos Silva (1-3, 8.48 ERA) on the 15-day disabled list with right shoulder inflammation, retroactive to Thursday.

BOXING: : Chad Dawson successfully defended his International Boxing Federation and International Boxing Organization light heavyweight titles in Las Vegas, unanimously outpointing Antonio Tarver in a rematch of their October fight.

CYCLING: : The Astana squad of Lance Armstrong, who is competing in his first major race since winning his seventh consecutive Tour de France in 2005, finished third in the team time trial Saturday in Venice to start the Giro d'Italia.

TENNIS: : Top-ranked Dinara Safina won her first WTA title of the year by defeating fellow Russian Svetlana Kuznetsova, 6-3, 6-2, in the final of the Italian Open in Rome.