Mike Flanagan pitched a five-hitter, Wayne Gross homered and Eddie Murray extended his hitting streak to a club-record 22 games with a homer tonight as the Baltimore Orioles beat Detroit, 3-1, ending the Tigers' four-game winning streak.

It was the Orioles' third straight victory and sixth in their last eight games. For the 27,440 fans at Memorial Stadium, the game felt like a typical, late-season Orioles' triumph during a pennant drive, except that this season, Baltimore is relegated to chasing Toronto for second place. The Orioles trail the Blue Jays by 1 1/2 games.

Despite the defeat, the Tigers remained 11 1/2 games ahead of Toronto in the American League East and moved a step closer to the title because of the Blue Jays' loss to New York. Any combination of Detroit victories and Toronto defeats that total eight will clinch the division title for the Tigers.

Flanagan (12-12) walked two batters and struck out five in pitching his 10th complete game of the season. In his last six starts, Flanagan is 3-1 with a 2.51 ERA. Against Detroit this season, he has allowed only two earned runs in 35 innings.

But, as usual, Flanagan's victory was a struggle. His worst enemies this season have been his teammates, who have scored three runs or fewer in 16 of his past 25 starts.

"I just feel sorry he's 12-12. He should be about 18-7," said Ray Miller, Baltimore pitching coach. "This is the best he's ever pitched. Even in his Cy Young year (1979), he was knocked out four or five times early. This year he's consistent in getting seven or eight strong innings."

For his part, Flanagan seems undisturbed by the lack of support. "It makes us better pitchers in the long run," said Flanagan. "Early in my career it would have bothered me. It does play on you a while. You try to block it out."

Because the Orioles squandered early opportunities against Detroit starter Juan Berenguer (8-10), Flanagan was still pitching in dangerous times in the ninth, protecting a two-run lead. He allowed a leadoff single to Kirk Gibson. Lance Parrish then hit two monstrous foul balls that barely missed being game-tying homers before flying out to right fielder Mike Young.

"I wound up and I threw it as hard as I can and figured Parrish would hit it to center field," said Flanagan, a 1-0 loser to Berenguer last week. "When he pulled it foul to left, it sort of blew my game plan."

With two outs, Chet Lemon walked, advancing Gibson to second. But Tom Brookens, a .236 hitter, struck out to end the game.

Murray's double play ground out scored Young in the first inning for a 1-0 Baltimore lead. In the second, Berenguer, constantly getting behind the hitters, offered Gross a 3-1 fast ball. Gross hit it over the 387-foot sign in right-center for his 20th homer, tops amoung American League third basemen.

Detroit closed to 2-1 on Gibson's fourth-inning homer, his third in four games. Berenguer left after seven innings, and an old Baltimore nemesis, Aurelio Lopez, replaced him.

Last week, Young asked Murray for advice on Lopez before hitting a homer. Tonight, Murray got a chance to heed his own words. With one out in the eighth, he hit a 1-0 fast ball deep into the right field bleachers for his 27th homer and 106th RBI.

"You just can't look for the fast ball. Lopez can throw five different pitches," said Murray, hitting .442 since Aug. 17. "The last couple of days I've been thinking about (the hitting streak) because people keep asking me about it. The last time up I told myself to be a little more patient up there."

Murray's 22-game streak set an Orioles' single-season club record and tied the mark over two seasons, both set by Doug DeCinces.