The rampaging Baltimore Orioles swept a doubleheader tonight, rationing the Toronto Blue Jays to only one run.

Scott McGregor scattered seven hits in the opener and the Orioles prevailed, 6-1. Steve Stone and Don Stanhouse, the latter throwing the final out, limited the Jays to four hits to complete the twin killing, 4-0.

During a month known for weddings, the Birds have cherished first place in the American League East like a bride, winning 20 of their last 23 games. Last-place Toronto, on the other hand, has lost its last 10 meetings with Baltimore, dating into last season.

In the nightcap, the Blue Jays did little to threaten their lack of success against the Orioles, until the final inning. Stone, now 6-5, finally became erractic after hurling five pefect innings out of the first eight.

The Blue Jays got their second walk of the game off the veteran righthander and one out later, Rick Bosetti singled. Stone retired Rico Carty but walked John Mayberry to load the bases.

Oriole Manager Earl Weaver then made his second appearance on the mound in the innings.

"He said he felt good, but you don't go out and walk two men with a four-run lead," said Weaver. "He had given us everything he could but 16 players have hit homers off him this year. I've got a guy (Stanhouse) in the bullpen who has thrown one ball (hit) out of here in two years. To protect the shutout in that position doesn't mean as much as does having the tying run at the plate."

Stanhouse forced Al Woods to hit a 2-1 pitch into a fielder's choice, shortstop Kiko Garcia nailing Mayberry on the force at second.

"I relaxed until I tensed up, trying too hard to throw strikes for the complete-game shutout," offered the bespectacled Stone, who has watched Stanhouse (nine saves) quench the potential fire on five of Stone's victories. "I was throwing harder in the ninth than in any other inning."

The Orioles got on the board in the third inning when Pat Kelly's 400-foot shot glanced off the upraised glove of center fielder Bosetti and fell over the fence. In the sixth, Kelly scored as Gary Roenicke hit into a double play, clearing the bases, and John Lowestein followed with his seventh homer for a 3-0 score.

Kelly wrapped up the scoring in the eighth when he doubled and scored his third run on Lowenstein's single.

"Guys like Lowenstein and Kelly are why I thought we'd have a good ball club in spring training," said Weaver. "We're doing nothing more than accomplishing what we're capable of and, when we do that, we're going to win our share of games."

Roenicke, playing in center in place of Al Bumbry (strained knee), made a key in the nightcap.

Carty had doubled to lead off the fifth and Mayberry sent a 300-foot-plus one hopper to Roenicke. Carty wheeled around third with "score" in his eyes, but wisely looked up long enough to see Roenicke's perfect toss reach catcher Dave Skaggs on the fly and scampered back to third. A shocked Mayberry was run down as he tried to stretch his hit into a double.

McGregor made short work of Toronto in the opener, needing only 1 hour 56 minutes to even his record at 2-2. The southpaw threw a stingy 98 pitches - only 28 of them balls - walked only one Blue Jay and fanned two.

Rich Dauer hit a two-run single in the second inning as part of a busy game in which the Oriole second baseman handled 10 putouts and three assists afield. That and successive home runs in the sixth by Doug DeCinces and Lee May carried McGregor along.

Dave Stieb, making his major league debut for Toronto, retired 13 consecutive batters before walking Ken Singleton with two out in the sixth. DeCinces followed with his homer and with 400-footer over the fence. CAPTION: Picture, Greg Luzinski of Phillies scores on Gary Maddox' fly in 8-7 win over Cards. Catcher Terry Kennedy muffs throw. UPI