Phoenix ? Mark Prior looks as if he’s ready to become the dominant ace everyone is expecting.

Prior pitched four shutout innings for his first victory of the spring as the Cubs beat Oakland, 8-6, in a split-squad game Sunday.

The 22-year-old right-hander yielded five hits and struck out three, while Oakland aces Mark Mulder and Tim Hudson allowed four runs apiece.

“There was a lot of good pitching out there,” Cubs manager Dusty Baker said. “I think our guy had the best day, but all three guys pitched like they’re ready for the season.”

Considered one of the best college pitchers ever, Prior was selected by the Cubs out of Southern California with the second overall pick in the 2001 draft.

He advanced rapidly through the minors and went 6-6 with a 3.32 ERA as a rookie last year, striking out 147 in 1162¼3 innings.

After giving up a pair of homers in his first inning of spring training, Prior has not allowed a run in his last two outings.

Alex Gonzalez had two hits and an RBI for Chicago, while Sammy Sosa went 2-for-3 with a double.

Mulder allowed four runs on five hits in the first inning. Overall, he yielded seven hits and three walks in four innings for his first loss this spring.

“I hadn’t found a rhythm (in the first inning),” Mulder said. “I could even feel myself doing it, stopping my arm before I finished my pitches.”

Frank Menechino went 4-for-4 for the A’s, raising his spring average to .652 with eight straight hits altogether.

Hudson did much of his work from the stretch. The game originally was scheduled for 10 innings to allow Mulder and Hudson to throw five innings apiece, but Mulder reached his scheduled pitch count in four innings.

White Sox

Tucson, Ariz. — Chicago renewed left-hander Mark Buehrle’s contract for this season for $445,000 after being unable to reach a long-term deal. Buehrle will be eligible for salary arbitration after this season and free agency after the 2006 season. One of the AL’s best young pitchers, Buehrle is 35-20 with a 3.44 ERA over the last two years and made the All-Star squad last season when he went 19-12 with a 3.58 ERA.

Padres

Peoria, Ariz. — San Diego left fielder Phil Nevin will have surgery Tuesday on his injured left shoulder and could miss the entire season. Nevin dislocated the shoulder making a diving catch in an exhibition game Thursday against the Colorado Rockies. Nevin will have the surgery at Scripps Clinic to repair damage to the joint capsule and tearing of the labrum. An MRI showed no tearing of the rotator cuff.

Reds

Sarasota, Fla. — Cincinnati outfielder Austin Kearns will have surgery to remove bone chips from his left elbow today and is expected to miss seven to 10 days. An MRI exam Sunday found chips in Kearns’ non-throwing elbow.

Indians

Winter Haven, Fla. — Reliever Mark Wohlers will leave training camp to have his sore right elbow examined. James Andrews, a sports orthopedic surgeon, will examine the elbow today. He and Cincinnati doctor Timothy Kremchek operated on it in 1999.

Yankees

Tampa, Fla. — New York agreed to terms Sunday on a minor-league contract with right-hander Ramon Ramirez of the Hiroshima Carp. The Yankees won the right to negotiate with the pitcher after a bid of $350,000 was accepted by the team.