If the Baltimore Orioles have it in them to win the second-season division flag by a decisive knockout, then their blitz will probably have to come in the 15-game homestead that began last night with a resounding, emblematic victory.

Pitching, coposed more of artistry than brute exertion, and home run hitting with loads of birds on the bases, have been the hallmark of Baltimore binges in recent years.

Both those commodities -- a Scott McGregor five-hitter and an eighth-inning Doug DeCinces grand slam -- were on display in last night's 6-2 win over California before 16,093 fans at Memorial Stadium.

All the Orioles assume they will be in a pennant race until the end. However, after their fourth straight victory last night, another possibility presented itself.

"How about if we just jump out in front and let somebody chase us for a change?" asked Ken Singleton in the locker room.

"We might be about ready for one of our moves," said the leader of this team which is known for mixing patient and dull .500 ball with three-to-four week orgies (such as a 22-3 explosion this spring).

Certainly, with the Birds just half a game out of first place, the familiar ingredients are present.

"I feel sooooo relaxed and confident," said DeCinces, who has hit .386 since the strike with 15 RBI in 16 games, including two grand slams.

This evening, DeCinces tranformed a pitching duel between McGregor and California's Ken Forsch (10-6) with one swing which provided thunder on a balmy night.

With the O's leading, 2-1, the bases loaded and one out in the eighth, Gene Mauch called in bullpen ace Don Aase. DeCinces hit Aase's first pitch, a fast ball, so far that he waited at home plate to supervise down-range sighting.

"For a split second, I thought maybe, just maybe, I had hit it entirely over the bleachers," said DeCinces, knowing that only Frank Robinson has ever done that. The ball landed five yards fair and well above the mid-bleacher exitway -- a 450-foot blast.

But that towering rocket couldn't overshadow the splendid McGregor (9-3), who has quietly become one of the sport's dozen best starters.

"I was reading the hitters well," he said after his 97-pitch gem -- marred only by two Bobby Grich homers -- had given him his ninth straight victory over the Angels.

What in the world is "reading the hitters?"

"It's looking at a hitter, studying his feet and his stance, the way he moves, and sensing what he's expecting . . . then doing the opposite," said MacGregor.

It's the key to his success," said Manager Earl Weaver. "It's an instinct that can't be taught. And it's what Scotty's got that all them guys with great stuff and 'great potential' can't ever figure out."

"You watch the hitters all the time, then, suddenly somebody looks different up there and the alarm goes off," said McGregor.

In his own way, the mesmerizing McGregor is in his own inviolable world. "It's a pleasure when you're doing it right," he said.

Several key Orioles -- such as Al Bumbry, and switch hitters Singleton and Eddie Murray -- are temporarily in that blessed state where hitting a baseball or throwing it seems inexplicably easy and self evident.