Baltimore Oriole pitcher Steve Stone is in a groove. The 32-year-old right-hander won his seventh straight game tonight, a five-hit 9-0 victory over the Seattle Mariners at Memorial Stadium.

With offensive help from Ken Singleton (two hits) and Eddie Murray (four runs batted in), Stone (9-3) breezed to his third consecutive complete game. Stone is tied four second in victories among American League Pitchers

When asked if he could remember the last time when he was in such a groove, Stone replied, "Sure, It was in 1967 when I was in Cleveland Class A. That was the last time. No, seriously though, I've never been in this good a groove in the big legues." Indeed, this is the best start Stone has gotten off to in his nine-year major league career.

Tonight's win before 28,000 was Stone's second complete-game win over the Mariners in nine days. He was allowed a single run in those innings.

"Seattle is no pushover now," Stone said. "They've got (Juan) Beniquez, (Dan) Meyer and (Tom) Paciorek in the middle of that lineup. They've got some punch. I'm just in a pretty good groove right now and (the Orioles) are giving me four, five runs a ball game -- nine tonight -- and it's hard to lose with that kind of support."

The only support Stone needed came in the fourth inning when Singleton and Rich Dauer singled and Murray ripped losing pitcher Dave Robert's first pitch far into the left-field bleachers for his 12th home run.

The Birds made No. 3 wild on the scoreboard by tagging pitchers Jim Beattie and Rob Dressler for three runs in the fifth and again in the sixth. bBeattie relieved Roberts, who won his only game of the year last week against the Orioles in Seattle.

Baltimore's Mary Corey greeted ex-Yankee Beattie with an opposite-field single that led to the three fifth-inning runs. Murray's fourth RBI of the night, a bloop single to left field, was the big hit. Murray leads the club in runs batted in with 45 and has 25 in his last 27 games.

The sixth-inning runs scored on a double by Rick Dempsey, two walks, RBI groundouts by Al Bumbry and Dauer, plus a run-scoring single by Singleton.

The victory kept the Birds 9 1/2 games behind the front-running Yankees, who won earlier today. The O's have won five of six games on this homestand which will continue Sunday afternoon against Seattle.

Stone, who has not lost since May 5, retired 11 Mariners in a row in the middle innings before giving up a harmless single to Bruce Bochte to lead off the seventh. Stone has never been a strikeout pitcher but took over the team lead with 56 by whiffing seven tonight.

His most masterful pitching came in the fifth inning when he faced Seattle first baseman Ted Cox, whose three-run homer in the ninth inning Friday night beat Jim Palmer.

Cox slammed Stone's first pitch far down the leftfield line, missing a homer by inches when the ball curved foul. Stone tried to sneak another fast ball by Cox, but the right-hander blasted it down the right-field line, this one curving foul by a few feet.

So Stone whizzed a third fast ball by the ear of the sprawling Cox, backing him off the plate. Then he broke off a sharp curve, striking out Cox on a feeble swing.

"The pitch that knocked him down just got away from me," Stone said. "I wasn't trying to knock him down. I never throw at hitters." Stone breezed thereafter, giving up only two singles.

"We're just about ready to start streaking now," he said confidently. "Our starting pitching and defense is beginning to come around. We (the starting pitchers) have completed four of our last five starts and 11 of 20. Pitching and defense -- that's how we did it last year."

The performance delighted the fans, who turn out in droves when Stone pitches, for good reason.

Stone is 14-2 at Memorial Stadium since joining the Orioles at the beginning of last season.