The Baltimore Orioles were up to their usual disgusting April shenanigans today.

The Birds, who swing the bat in spring as though it still has the doughnut attached, struck out 15 times against Boston's Frank Tanana and Mark Clear; marvelous Mark Belanger led the way with four Ks.

Also, Rich Dauer made an error on a routine grounder, breaking his streak of 400 consecutive errorless chances over 76 games and continuing an O's tradition of fielding in chilly weather as though the ball were radioactive.

The Birds didn't hit a homer. They seldom do in April.

And, as always, Baltimore got its worst injury news right up front with the word that Eddie Murray still feels so miserable with his viral infection that it may yet be another day or three before he feels up to playing.

No team so good has mastered the art of looking so lousy as the Orioles in accursed April, a plague month in which, since 1975, they have a 55-63 record.

Oooops. . .

What's that you say?

The Orioles won this afternoon?

They not only won, but they were in midseason, warm-weather form, defeating the Boston Red Sox, 7-2.

Mike Flanagan pitched a seven-strikeout four-hitter in which he mowed down the last seven Red Sox hitters like wheat before the scythe. Was that really Flanagan saying, "I haven't pitched a power game like this since, eh . . . Well, heck, I haven't felt this overpowering since the ("79) World Series."

Could it have been Doug ("Doug, are you all right, Doug?") DeCinces, the injury-prone third baseman who could slash his wrists while buttering toast, who contributed a single, two ringing doubles and four RBI? Could this fellow, mashing balls off various parts of the left field fence, be the same chap who entered the game with a .111 slugging percentage?

And what of Dauer, the Oriole who loathes April because his career average is .197 for the month, including memorable seasons when he was 0 for April and 1 for April. Was that Dauer going three for four, plus a walk, to raise his average to .342?

Remarkable as it seems, it only takes one game to lure a team into thinking that it sees the big turn-around on the horizon. Not much should be read into one skimpy victory by a team that has been playing poorly. However, the O's, coming off four straight loses, including a 23-8 (combined score) crushing in a doubleheader in Chicago, were in a mood to think well of themselves today.

"This was a big game for me because it shows me that all my off-season (shoulder) rehabilitation work has made me a power pitcher again," said Flanagan, who was throwing 88 mph in the first inning and 87 in the ninth.

"And it was a big game for Doug, because he was having a terrible spring (3-for-27). And it was a big game for the team because this begins a 12-game home stand and we're determined not to let this slump stuff go on as long as it did last year (when Baltimore started 6-11, reached 28-30 and spotted New York 11 games in the lost column).

A cynic would note that the Birds (4-6) still have only one complete game and two victories among their vaunted starting rotation. A gloomster would point out that the oft-rained-upon O's still have played games on back-to-back days only once this season.

"If it don't rain Sunday, and we get to play two days in a row, then I'll believe maybe our luck is changing," grumbled Manager Earl Weaver. "Right now, we got no pitching rotation and the hitters got no timing. We need to play 12 consecutive days (at home) without a postponement, and maybe even get some decent baseball weather.

"However," added the manager, huddled in his heaviest jacket, looking at the dark, scudding clouds and the chilly winds, that held the crowd to 19,634, "I ain't callin' this baseball weather."

After this smooth, dozen-hit win, in which the Birds beat one of their nemeses, Frank Tanana, with three runs on six singles in the fourth and three runs on a bases-clearing, DeCinces double in the fifth, the O's chose to look for rosy omens.

"Almost every pitcher has one key pitch that sets up all his others," said Flanagan. "For Scotty (McGregor), it's getting his changeup over for strikes.For Jim (Palmer), it's getting people to swing at his high fast ball. For (Steve) Stone, it's getting his big curve over the plate consistently. For me, it's having a hard enough fast ball, on the fists, so that hitters can't pull me.

"Last year, when I worked inside, instead of strikeouts and pop-ups, the good hitters would pull me hard and the poor hitters would still fight off the pitch. For me, that's trouble. I turned into a finesse pitcher (and went 16-13). Now, the fast ball seems to be back. And that helps every other pitcher."

Only one dampening thought would not leave the O's today: when will Murray be back?

"I've run every conceivable test," the team doctor, Leonard Wallenstein, told Weaver. "I can't find anything. He just has to rest until he feels better and this myalgia (pain in the muscles) goes away."

Such can't-find-a-thing-wrong diagnoses always trouble ball clubs, since team doctors are often looked upon with wild, and sometimes unfounded, suspicion. Four Oriole starting pitchers, for instance, have their personal arm doctors, keeping Wallenstein at, shall we say, arm's length.

"I just hope there really isn't anything wrong with Eddie," said Flanagan.