Unbeaten Steve Carlton won his fifth game, driving in the go-ahead fun in the sixth inning, as the Phillies defeated the San Francisco Giants, 6-4, last night in Philadelphia.

Carlton gave up four runs on five hits in the first three innings, then held the Giants to two more hits. He fanned eight in his 254th victory.

Trailing, 4-3, with one out in the sixth, the Phillies tied on consecutive singles by Garry Maddox, Larry Bowa and Bob Boone off Allen Ripley (1-3). Left fielder Larry Herndon bobbled Boone's hit for an error, enabling Bowa to take third. Carlton then grounded to shortstop John LeMaster, who bobbled the ball before throwing out Carlton, allowing Bowa to score.

The Phillies added a run in the seventh when Mike Schmidt reached on a fielder's choice, moved to second on a balk, stole third and scored on Gary Matthews' ground out.

A bases-loaded squeeze bunt by Mike Sadek and Ripley's two-out single gave the Giants three runs in the second. They made it 4-0 in the third as Enos Cabell doubled, stole third and scored on Herndon's single.

Philadelphia scored single runs in the third, fourth and fifth on Greg Gross' fly ball, after Carlton tripled, and singles by Bowa and Pete Rose.