Right-hander Storm Davis, aided by some fine defensive plays, limited Seattle to three hits tonight and the Baltimore Orioles shut out the Mariners for the second straight game, this time 6-0.

Davis walked only one and struck out five in his best effort of a disappointing season. His third win in a row lifted him over the .500 mark at 8-7, after a bad beginning that found him assigned briefly to bullpen duty.

"The guys played great defense and scored six runs. That takes the pressure off," Davis said.

The Orioles' eighth straight victory at home enabled them to take third place in the American League East, one percentage point ahead of Detroit.

Back in April, any thoughts of slipping ahead of the Tigers at the end of August would have been associated with a pennant race, but the Orioles remained 11 1/2 games behind Toronto and for the moment must be content with other milestones, of which there were several tonight.

Floyd Rayford was the Orioles' principal batting hero, reaching the 10-home run mark for the first time and embellishing that accomplishment with his first major league triple.

Rick Dempsey also hit his 10th homer, enabling the Orioles to become the ninth team in major league history with nine men in double figures. When Lee Lacy, on hold at nine, hits his next homer, Baltimore will have the record by itself.

Eddie Murray had two doubles and boosted his batting average to .301, the first time he's been over .300 since June 18.

Alan Wiggins had a perfect night at the plate, with three hits and two walks, but was less successful on the bases, being picked off twice.

Second baseman Wiggins made an outstanding play in the seventh, as he drifted behind second base to throw out Jim Presley. Shortstop Cal Ripken executed a pair of beauties, too, moving left to scoop up Al Cowens' grounder in the second and making a back-handed stop deep in the hole to retire Bob Kearney in the sixth.

Davis gave his mates full credit and also thanked Mike Boddicker, who blanked the Mariners Thursday.

"I like to throw behind Mike," Davis said. "I did it a lot in '83 and '84 with some success. Mike throws a lot of guys' timing off.

"Physically, I didn't feel that good tonight. I was a little drowsy. But that happens some nights. You go out there and throw good anyway.

"I got my slider in enough to keep the righties honest, I got a couple of line-drive outs, there were some great plays by Wiggie and Rip, and I got a key popup with (Alvin) Davis."

Davis retired the first 12 Mariners before Ken Phelps singled to right opening the fifth. He did not advance.

With two out in the sixth, Jack Perconte walked and Phil Bradley lined an opposite-field double to right. That brought up Alvin Davis, who popped up to third baseman Rayford.

The Mariners' only other base runner was Perconte, who singled to open the ninth and was erased in a double play started by Ripken.

The losing pitcher was Mark Langston (7-11), who, like Davis, is struggling after winning 17 games as a rookie in 1984. Langston departed in the fifth and might have been gone sooner except for his success in nailing Wiggins, the embarrassed leadoff man in both the first and third.

Each time Langston did it with a quick move off the rubber and a remarkably strong throw without stepping toward first.

Seattle's defense betrayed Langston in the second inning. With two out and Murray on first, third baseman Presley mishandled Rayford's grounder. Both runners advanced on a passed ball and scored on a double to right center by John Shelby, playing in place of injured Fred Lynn.

Langston was struck in the left foot by Gary Roenicke's grounder opening the fourth. Although the ball caromed to first baseman Alvin Davis for an out and Langston said it did not affect him, after he tested the foot he was touched for Rayford's homer over the 405-foot mark in center.

One out later, Dempsey lofted a rare homer that landed in the upper deck in left, where only a few seats jut into fair territory beyond the foul pole.

Langston departed in the fifth, following Murray's second double and an RBI single by Roenicke. Rayford greeted reliever Jack Lazorko with a line drive off that familiar 405 mark, his first triple in 649 major league at bats.

"It was no big deal," Rayford insisted. "The ball hit the wall and I had a lot of time."