After his teammates had wasted scoring opportunities all night, reliever Nate Snell of the Baltimore Orioles walked Gorman Thomas on four pitches with the bases loaded in the ninth inning tonight to give the Seattle Mariners a 4-3 victory.

Jack Perconte started Snell's problems with a one-out single to center. Phil Bradley singled and Al Cowens walked on four pitches. Snell (3-2), unhappy about the ball and strike calls, threw his glove high above the mound after walking Thomas on a pitch in the dirt.

"Snell's all right," Manager Earl Weaver of the Orioles said. "He's done his share around here. We'll win eight of the next nine and see where we stand then."

Winner Mike Moore (11-7) persevered with an eight-hitter for his seventh complete game this year.

The Orioles seemingly got a head start toward their seventh straight victory in the first inning when Alan Wiggins led off with a double, stole third and scored on Lee Lacy's grounder. They put two on with one out in the second but Rick Dempsey grounded into a double play.

The Orioles' starter, Mike Flanagan, lasted seven innings. He yielded two 410-foot outs to center field in the bottom of the first, but it wasn't until the third that the Mariners tied the game when Bradley hit his 17th home run this season.

Alvin Davis led off Seattle's fourth with a single to center and Jim Presley grounded a single into the hole past shortstop Cal Ripken. Davis stopped at second but took third after Dave Henderson flied to Lee Lacy in right field. Tim Kearney bounced back to Flanagan, who threw him out at first, putting runners on second and third. No. 9 hitter Spike Owen singled under third baseman Floyd Rayford's glove for two runs. When left fielder Mike Young's throw home sailed over catcher Dempsey's head, Owen went to third, but Perconte struck out.

Larry Sheets hit his 14th home run in the fifth, then, one batter later, Dempsey tied the game with his eighth.