Now, on top of everything, Dennis Martinez pitches a shutout.

For those followers of the Baltimore Orioles who thought that no more pieces could possibly fall into place in the jigsaw puzzle of a splendid season, the Orioles found one last corner of their picture that could be improved tonight.

The most unlucky of all Orioles--Dennis (The Menace) Martinez, who had started 22 games this season and helped the team lose 16 of them--finally got a chance to redeem himself after 40 nights in the exile of the bullpen.

On a chilly evening in Fenway Park, Martinez worked six victorious shutout innings as the Orioles beat Boston, 5-0, with almost contemptuous ease for their sixth consecutive victory in their latest incredible winning streak.

Perhaps even the Orioles themselves have not quite grasped how well they are playing, now that they are finally in perfect health and spirits. In their last 22 games, of which they've won 19, the Awesome Orioles--for they are certainly nothing less at the moment--have outscored their foes by 142 runs to 53.

Ever since their back-to-back, extra-inning wins over Toronto in Memorial Stadium put the match to the dynamite, the Orioles have been raining debris all over the league.

The Orioles' sights now appear set not only on winning the American League East (their lead remains at 5 1/2 games) but a 100-win season as well. The Orioles, who're on a 46-19 binge, can slow down a bit and merely play 12-7 ball for the rest of the year to reach that plateau for the third time in five seasons.

Baltimore's records and achievements have been mounting up so fast of late that those close to the club are almost dizzy from sifting the truly exceptional from the merely marvelous.

For instance:

* Left fielder Gary Roenicke's two-run homer off the light tower above the Green Monster made a loser of John Tudor tonight. The Orioles left fielders have now driven in 17 runs in the last six games. Last season, when that position contributed 41 homers and 123 RBI, it was considered one of the flukes of the era. Now, the same folks in left have 32 homers, 118 RBI and a .301 average. If the AL MVP were awarded by position, wouldn't Gary Roenicke, John Lowenstein and their occasional cohorts have a lock on the honor?

"I hate to do so well when I'm playing so little because I don't want that (platooning) to happen the rest of my career," said Roenicke, who has 19 homers and 61 RBI in a paltry 288 at bats.

"No, I don't think people around the league really understand what we've done (in left field)," said Roenicke. "I'd like to play more. If they wanted me to try to play third base next year, I would try it. But it does seem kinda crazy to break up what we've got going. If you win it all, you wouldn't want to change much."

"It is a difficult phenomenon to fathom, even if you are part of it," offered Lowenstein in his deadpan-scholar way.

* Sammy Stewart continued to reassert himself as a bullpen pitcher who can work long or middle relief, as he did splendidly in '81. Tonight, he cleaned up his sixth save, to go with an 8-3 record, with three innings of confident work. Since Aug. 4, Stewart's ERA is 1.99 over 13 unbeaten appearances.

Ever since his acute embarrassment after being arrested for drunk driving in July, plus other personal problems, the free-spirited, sometimes undiscipled Stewart has done an abrupt about-face in attitude.

"I think my attitude's improved and my concentration. I'm glad I got this out at 28, not 32, when it's too late to turn," said Stewart, who has been getting professional counseling. "I'm trying to let criticism help me, instead of being moody. It's time for me to find out how good I can be if I give myself a real shot."

* The Orioles' MVP twins, Cal Ripken and Eddie Murray, continued their friendly rivalry as Ripken had three hits and Murray got the game's first and last RBI with a double and single. Ripken, who's only made one error at short in a month, has been scalding with the bat for 37 games (.365). Now, Murray, merely warm in recent weeks, has six hits in his last eight at bats and looks on the verge of a big breakout.

* In addition to all this, Martinez finally looked like his best self this evening. His fast ball, curve and control were all of 18-game-winner quality, as they have always been. Martinez had one 10-pitch battle with Wade Boggs, the AL's leading hitter, which ending with Martinez striking out a man who has only struck out 34 times this year.

"This has been a bad year for me," said Martinez who returned here today after spending two days in Miami with his mother, who had surgery for gall stones. Martinez's son is also in the hospital for possible surgery on his foot.

"I told myself to win this for my mother and my son. They will feel better when I call them in the morning."

Martinez will feel better, too. His future with the Orioles has been in jeopardy. Last month, Martinez went to General Manager Hank Peters and asked, "What is my role here? What's going on? Do I have a future here?

"He told me that they haven't given up on me, that I'd had six good years for them and that every pitcher has a bad season some time. That made me real happy. I wasn't mad any more. They still have confidence in me . . . I've been throwing good in the bullpen, keeping strong, and now I just want to help the team any way I can--out of the bullpen or anything--the rest of the year.

"I want them to say, 'Dennis is ready.' I want them to trust me, like they do Sammy."

At this moment, the Orioles' puzzle is complete--every piece in place. The subject of the portrait is obvious: a powerful world championship team.

That is, if the pieces stay in place.

And that is another question.