Ron Guidry of the New York Yankees pitched his second straight shutout yesterday, a four-hit 4-0 victory over the Tigers in Detroit.

Don Baylor had a two-run homer in the sixth inning. The Yankees scored once in the first, providing the only run Guidry needed, and added a run in the fourth.

The loss, which ended the Tigers' four-game winning streak, was only their third in 13 games.

Guidry (8-3) beat the Baltimore Orioles, 10-0, Monday. He has allowed one run in his last 25 1/3 innings. The last run he gave up was June 13 against the Blue Jays, Toronto scoring in the eighth inning after he had pitched scoreless ball. He was relieved after 7 1/3 innings and Toronto won, 3-2, in extra innings.

"It's not 1978 where I can just blow the fast ball past them," said Guidry, who has walked only 14 batters in 15 starts this season. "I can still throw hard, but I have to mix it up and set them up. To be a good pitcher, you have to accept the fact that you might have to change -- especially if you want to stay around. I'm not hardheaded."

"He's throwing as well now as he was a couple of years ago," said Detroit's Kirk Gibson, who had his hitting streak ended at eight games.

Guidry struck out the side in the first inning and finished with six strikeouts. He didn't allow a walk in winning his seventh straight decision and gave up only one hit in the last five innings.

Loser Dan Petry (9-5) went all the way, giving up 11 hits, walking two and striking out five. He continues to lead the American League in victories despite winning only once since May 22.

Ken Griffey walked in the Yankees' first, stole second and scored on Dave Winfield's two-out single. Winfield doubled in the fourth and scored on Ron Hassey's single.

Don Mattingly singled in the sixth and scored ahead of Baylor's 12th home run, which hit the facing of the second deck in left field.

Newly acquired Doug Flynn played second base for the Tigers and went one for three.