Sammy Stewart should have stayed in the snug Oriole clubhouse, where the heat was on and his American League earned run average lead would have been safe.

But because Jim Palmer's right forearm muscle was hurting, Stewart volunteered to risk his league-leading 1.95 ERA in the raw, windy cold of Memorial Stadium against the New York Yankees tonight. Stewart retired only five Yankee batters, allowing five earned runs and two home runs as the Orioles lost, 9-0, before a crowd significantly smaller than the paid attendance of 25,748.

Stewart's ERA rose to 2.32, placing him third behind Yankee winner Dave Righetti, who shut out the Orioles for seven innings and lowered his ERA to 2.05, and Chicago's Dennis Lamp (2.29). Righetti, a prime candidate for rookie of the year, needs 1 2/3 innings to qualify for the title and probably will pitch here Sunday.

With two home runs by Dave Winfield and his own four-hit pitching putting the Yankees comfortably ahead, Righetti was removed before the eighth inning. Reliever Goose Gossage, who hadn't pitched since Sept. 15, when he incurred a pulled groin, pitched the last two innings. Yankee Manager Bob Lemon said he wanted Gossage to get some work before the division playoffs start next week.

"I knew Goose needed to work," Righetti said afterward. "Bob told me when he took me out, 'You pitched real well. We'll work something out on Sunday,' "

Righetti said: "If it feels good I'll pitch on Sunday. If it's stiff, I won't test it. It's more important to be healthy into the playoffs."

Stewart already had pitched enough innings -- one for each game his team played in this abbreviated season -- but decided to go tonight with only three days rest after shutting out the Tigers for 8 1/3 innings Monday.

"I don't feel bad at all," Stewart said. "Earl (Weaver, the Oriole manager) asked me yesterday if I wanted to sit on it or start. With Jim hurt, I said I'd be glad to start. I wouldn't feel right just sitting in the bullpen, knowing I could be pitching. That would be no way to win the thing."

Before the midseason strike, this three-game series figured to be a glamor match up for the AL East pennant. But now the Yankees are awaiting the playoffs and the Orioles are awaiting the offseason.

New York won the game in the first five minutes.

After retiring Willie Randolph and Jerry Mumphrey to start the game, Stewart (4-8) watched Dave Winfield hit a 400-foot home run to left field into the teeth of a strong wind. Stewart walked Reggie Jackson on a full count, then allowed Graig Nettles -- a dead-pull left-handed hitter -- to hit a homer to the opposite field for a 3-0 Yankee lead.

Stewart's troubles continued in the second inning, when he walked two batters and gave up a single to Larry Milbourne to load the bases. Mumphrey's ground ball to first gave New York a 4-0 lead and a wild pitch made it 5-0.