Now, with the coming of the first week of summer, the Baltimore Orioles have begun to sniff a pennant race. It's an old Oriole custom that, in the spring, the Birds smell. But, in summer, they smell first place.

Tonight in Memorial Stadium, the Orioles, who are hot and heading toward torrid, beat the Detroit Tigers, 4-1, to send the befuddled Bengals to their 12th loss in 13 games.

With this crisp, authoritative victory, built on Dennis Martinez's seven-hit pitching and Gary Roenicke's three-run homer off Milt Wilcox, Baltimore not only passed Detroit in the AL East standings, moving into third place, but climbed to 4 1/2 games behind division-leading Boston.

The Orioles' scenario is so familiar, and is being executed with such calm confidence, that, for the moment, it has about it the tenor of inevitability. They now have won six of eight and 14 of 19.

In fact, their 26-13 pace since May 13 is an almost-perfect duplicate of their warm-weather pushes of 1979 and 1980 when the club won 100 games or more. Baltimore has outscored its foes by a whopping 69 runs in its last 56 games and, increasingly, begins to resemble the quality clubs of those two glory years, rather than the indecisive and worried team of '81 that actually was outscored for the whole season.

Perhaps the happiest of the 31,859 fans in this humid but loud ball yard was Orioles owner Edward Bennett Williams, who said, "Back (in April) when we were going so badly, Earl Weaver told me, 'Calm down. We'll reach .500 by June 6 and we'll be within four games of first place by the All-Star break. Then, there'll be a great pennant race, and we'll win it.'

"Well, we got to .500 on June 7. We're just 4 1/2 games out with another two weeks until the (All-Star) break. And my manager looks pretty smart."

The best Oriole news this night was that Martinez -- who has won 14 consecutive decisions in his home park since August of 1980 -- has continued his recent transformation into the kind of overwhelming power pitcher the Birds have always hoped he could be.

Tonight, Martinez, 8-4 and winner of six of his last seven decisions, did not allow a man past second base until the ninth, when he had a 4-0 lead. Then, Larry Herndon's double and Lou Whitaker's single kept him from what would have been his second shutout in a week.

Martinez is typical of a drastic change in the Orioles' pitching philosophy. In April and May, charts showed that their pitchers were throwing more breaking balls than fast balls. And getting clobbered.

Charts of previous seasons showed, according to the pitching coach, Ray (Rabbit) Miller, that "every Oriole 20-game winner in the history of the club had thrown at least 60 percent fast balls. Plenty threw 65 percent fast balls. We had that 60-40 ratio between fast balls and breaking balls entirely backwards."

"Earl loves the curve," said Martinez. "In the meetings, he says, 'Good fast ball hitter. Throw him the breaking ball.' So I throw the curve because, if I don't, I know Earl will be mad. Then, a few weeks ago, Rabbit says, 'It's your game, not Earl's. In the paper, it says the losing pitcher is Martinez, not Weaver.'

"In '81, when I led the league in wins, I went right after the hitters. This year, I got in a bad habit and I was the one getting hurt by the curve balls. Now, I'm going after them again.'"

This night, Martinez threw 85 fast balls out of 117 pitches and, in all, threw 85 strikes as he walked just one man. In his three-hit shutout of Cleveland on Monday, he walked no one. "Dennis is getting so boring," said Mike Flanagan, who has gone to an identical fast ball-first approach and has a 1.58 ERA in his last 80 innings.

"Martinez was just like the best National League pitchers," said Detroit's Enos Cabell. "Fast balls in and out. Stay ahead of the count. Challenge everybody. No walks." Those are the words the Orioles have been waiting years to hear about Martinez.

For both the Orioles and Tigers, this night had symbolic feeling, as though these clubs may have passed in the muggy night, heading rapidly in opposite directions.

Baseball's springs are a time for delightful hallucinations when almost any creditable team can give its fans palpitations with 50 or 75 games worth of pennant-quality play. But, then, the off days disappear, the doubleheaders mount and a team's depth of starting pitching and its depth on the bench begin to tell their tale.

The Orioles still don't know how high they will climb. But the Tigers are beginning to sense how quickly they may fall.

"Our fielding has been killing us," Manager Sparky Anderson said before the game. " . . . our overall defense -- including the little plays that don't show up in the box score -- are beating us."

To his chagrin, Anderson was right, again. That Tiger defense broke the 0-0 tie and gave momentum to the O's. Oh, yes, Anderson helped, too.

Jim Dwyer opened the Orioles' fifth with a bunt that should have been an out, but catcher Bill Fahey, giving Lance Parrish a night off, showed his Washington Senator bloodlines. He reached the ball, grabbed it before it could roll foul, then fell on his face as he tried to square up to throw. Base hit.

After a fly out, Anderson got smart. Presumably thinking he'd stolen a sign, he called two pitchouts to Rick Dempsey. Wilcox then walked Dempsey on four pitches.

Next, Lenn Sakata flied routinely to Kirk Gibson in center. When Gibson missed the cutoff man by about 50 feet, Dwyer gratefully trotted to third. That base meant a run as Al Bumbry followed with an infield hit off the glove of shortstop Alan Trammell, which wouldn't have scored Dwyer from second but did plate him from third.

In the sixth, the Orioles iced matters. Eddie Murray ripped a double to left-center and Cal Ripken Jr. walked. With two out, Wilcox tried to get cute to Roenicke, dropping down sidearm for a change-up fork ball. The pitch did nothing but hang in the geometrical center of the plate. Until, that is, Roenicke blasted it eight rows deep into the bleachers, sending Wilcox's amazingly bad career record against Baltimore to 1-10.

That homer, Roenicke's 15th, giving him a club-leading 40 RBI, further separated these two clubs. It's summer; Orioles rise, Tigers fall.