The clouds parted long enough for the Boston Red Sox to finally get their baseball season under way today and they responded by defeating the Orioles in the first game of a doubleheader, 2-0, before falling in the nightcap, 5-3.

Boston's season opener had been delayed three times, first by snowstorms in Chicago, then by Friday's snowstorm here which forced today's doubleheader. The weatherbeaten Red Sox acted as if they didn't believe fair skies could last the day, racing through the first game in a scant two hours behind the six-hit, shutout pitching of Dennis Eckersley.

Baltimore loser Scott McGregor pitched a six-hitter of his own, allowing only two singles and a double after giving up both runs in the third inning. But that was all Eckersley needed.

In the second game, Boston's grand old man, 42-year-old Carl Yastrzemski, had three hits, the first a two-run homer in the first inning off starter Dennis Martinez, but the Orioles came back to take the lead in the third and never relinquished it. Baltimore slapped around three Boston pitchers, getting 10 hits and a 5-2 lead before reliever Sammy Stewart stopped a Boston rally in the eighth and preserved Martinez's first victory this season.

A crowd of 21,268 convened for this rare daytime two-for-one bargain at Memorial Stadium. The temperature at game time was 47 and clouds never crossed the sun. There were clouds on the Oriole horizon, however. Pitcher Steve Stone has announced that he has reinjured his elbow and will not be coming off the disabled list Sunday, as the team had hoped. Stone indicated the elbow would take at least several weeks more to heal.

The Orioles hadn't played since Monday's opening day 13-5 rout of Kansas City, but if anyone was rusty today it appeared to be the hitters.

"It seemed like they were having trouble seeing the ball" in the bright sun, McGregor said. "Bah," responded Eckersley, "that's what they say every time I pitch good."

The Orioles' Eddie Murray, who batted in three runs in the second game after his four-RBI performance opening day, gave Eckersley his due. "It seemed like he was pitching out of the white house (a town house beyond center field that renders the ball practically invisible to hitters) all day," said Murray.

The Red Sox got their runs on Jim Rice's single up the middle, but McGregor almost escaped unscathed.

Catcher Gary Allenson doubled to start the third inning and Reid Nichols tried to bunt Allenson to third. But after the snows and rains of the last week, Nichols' bunt struck and died in the swamp in front of the plate. Catcher Joe Nolan scooped up the ball and threw to second, where Allenson was caught off base and tagged out.

Dwight Evans followed with a double, sending Nichols to third. So the Red Sox had two doubles sandwiched around a bunt, but no runs home. With two out and a 2-2 count, Rice's ground single rectified that.

"It was a good pitch" to Rice, McGregor said, a fast ball inside that the slugger managed to muscle over second base.

Boston came out swinging in the second game as Yastrzemski poked his 427th major league homer just over the left field wall at the 376-foot mark, Rick Miller scoring ahead of him.

But the Orioles responded with a run in their half of the inning on doubles by Rich Dauer and Murray, picked up two more and chased starter Bobby Ojeda in the third on a walk, singles by Dauer and Ken Singleton and Murray's RBI grounder, and scored a run in each of the fifth and sixth innings.

Martinez allowed just four hits after the first inning. He was relieved by Stewart with two out in the eighth, and Stewart made things interesting before sealing the victory.

Stewart came on with a 5-2 lead, Yastrzemski on first and Miller on third. Miller promptly scored on a passed ball, then Stewart walked Carney Lansford but retired Dave Stapleton on a foul pop.

He walked catcher Rick Gedman to start the ninth and gave up a single to Glenn Hoffman, putting men on first and second with none out. Gedman was replaced by pinch runner Nichols, who was picked off second by Stewart. After a ground out and another walk, Stewart whipped a called third strike past Dwight Evans for his first save this year.

The pickoff was a thing of beauty, Stewart turning awkwardly to his right and delivering a strike to shortstop Lenn Sakata, who had signaled for the play.

"A lot of people don't know about Sammy's (backward) pickoff move," Sakata said. He said it was hard for Nichols to hear his third-base coach's warnings over the roar of the crowd, and Sakata noticed Nichols wasn't responding when the shortstop ducked behind him, faking the pickoff. So he made the call, and it proved a good one.

If the performances by Stewart, McGregor and Martinez were buoying to the Orioles, the news about Stone was not. He said the injury will require "a lot of time" to cure. Reliever Tim Stoddard, who has a bad shoulder, appears to be doing better, although he has not been permitted to throw yet. He is scheduled to come off the disabled list April 22, and Pitching Coach Ray Miller said, "The doctor seems to think he'll be ready about then."