Josh Beckett had enough left to escape a seventh-inning jam and become the first Red Sox pitcher to win his first six starts since Roger Clemens in 1991.

The righthander struck out Mark Ellis with runners at first and second and two outs, and Boston went on last night to beat visiting Oakland, 6-4.Beckett (6-0) is the only pitcher with six wins this season, his second with Boston. Beckett has moved from the third-base side of the rubber to the middle this season and has relied more on an improved curveball and changeup after concentrating on his fastball in key situations last year.

He returned to the fastball, though, when he ended his night by striking out Ellis for the third time, on a 1-2 count. In seven innings, Beckett allowed three runs and six hits with seven strikeouts and two walks. It was only the second time this season he had allowed more than two runs.

He became the eighth Red Sox pitcher to win at least his first six starts. The team record of eight is shared by Babe Ruth in 1917, Dave Ferriss in 1945 and Roger Moret in 1973.

Hideki Okajima, the AL rookie of the month for April, pitched the eighth, his 14th consecutive scoreless inning in 14 games. Mike Timlin pitched the ninth for his first save of the season.

Oakland designated hitter Mike Piazza is expected to be sidelined 4-to-6 weeks with a strained right shoulder. He was injured diving into third base to avoid being tagged out.

In other AL games:

* At Kansas City, light-hitting Esteban German hit a three-run home run in the seventh inning to lead the Royals past the Los Angeles Angels, 3-1.

* At Detroit, Gary Sheffield went 4-for-4 with a home run and an RBI single, and Craig Monroe hit a tiebreaking homer in the sixth inning, leading the Tigers past Baltimore, 3-2.

* At St. Petersburg, Fla., pinch-hitter Dioner Navarro drove in the winning run with a grounder in the 10th inning, and Tampa Bay rallied past Minnesota, 4-3.

* At Seattle, Yuniesky Betancourt hit a tiebreaking homer in the seventh inning and Miguel Batista (3-2) gave up two runs and five hits in 7 1/3 innings as the Mariners beat the Chicago White Sox, 3-2.

* At Arlington, Texas, the game between the New York Yankees and Rangers was postponed by rain. It game will be made up as part of a doubleheader today.

* At Cleveland, David Dellucci singled and Travis Hafner doubled to drive him in with no outs in the 11th inning and the Indians beat Toronto, 7-6.

Noteworthy

* The New York Yankees fired strength and conditioning coach Marty Miller following a rash of injuries to the pitching staff that has contributed to the team's poor start. *