Orioles starter Dennis Martinez made a mental adjustment tonight and left the Detroit Tigers scratching their heads after Baltimore won, 3-1, to keep Detroit's magic number for clinching the American League East at seven.

The Orioles won the season series with Detroit, 7-6, and remain 2 1/2 games behind second-place Toronto in the division.

For Martinez, tonight's victory was meaningful despite the Orioles' position in the standings. It was another step in a rebuilding process. After entering an alcoholic rehabilitation center during the offseason, Martinez has started 18 games this year. In 14 of those, he has allowed three runs or fewer.

Martinez was not happy with his performance last Friday against Milwaukee, in which he lasted only 1 1/3 innings, his briefest stint of the season. Since then, he has been working with Elrod Hendricks, the Orioles' bullpen coach, on an attitude adjustment.

"After the game against Milwaukee," Martinez said, "I said something's wrong. After I walked (Cecil) Cooper, everything started falling apart. So when I threw on the side with Elrod, I worked with him and he said, 'Don't worry so much about the runner.' So I was more aggressive tonight. I concentrated more on the batter."

As Martinez trotted off the field with his sixth victory in 13 decisions, he gave Hendricks a grateful hug. After all, he allowed only six hits and struck out six in his second complete game of the season. Detroit starter Roger Mason allowed three runs in four innings to lose his first major league decision.

"You heard (the Tigers) say how good their lineup was left-handed against right-handed pitchers," said Orioles Manager Joe Altobelli. "When you can shut down their left-handed lineup the way he did tonight, you better believe he did a great job."

Martinez began by retiring the first 12 batters. By the time the Tigers got their first hit -- an infield single by catcher Lance Parrish in the fifth inning -- the Orioles were ahead, 3-0.

Eddie Murray led off the second with his 97th walk and went to third on Mike Young's double down the right field line. Murray scored on Wayne Gross' fly ball to center and Young soon followed when Lenn Sakata's high chopper down the third base line bounced past Darrell Evans.

The Orioles' extended the lead in the third when John Shelby hit a ground-rule double to left, stole third and scored when Parrish threw wide of the bag. Cal Ripken then broke a one-for-22 skid with another ground-rule double, this one to right, but was stranded at second.

The way Martinez was pitching, that was all the Orioles needed. Even when the Tigers scored their run in the sixth, when Chet Lemon doubled, moved to third on a grounder and scored on a wild pitch, Martinez kept his composure.

"At that point I just wanted to stay cool," he said. "I knew it was my game."