As Doug DeCinces' rising, pulsating liner headed toward the left field bullpen tonight, the crowd of 35,456 in Memorial Stadium went stone silent for a split second.

For the next 15 minutes, they would be chanting "Doug, Doug, Doug," and spelling out "O-R-I-O-L-E-S" as they paid homage to a two-run, two-out homer in the bottom of the ninth that had salvaged a 6-5 victory over Detroit's stunned Tigers.

But at that instant as the ball burst from the bat and streaked toward victry, they could not believe it.

For the entire bottom of the ninth, the fans had been in a splendid tumult, rattling a pair of Tiger hurlers. But their volume was based on hope, nto certainty. How many times does a team, down two runs, pull out a game on demand?

Even as the big crowd pleaded, it seemed shocked by its own power. It barely seemed credible when the second O's batter of the last inning, Ken Singleton, after fouling off three two-strike pitches, crushed a 420-foot homer over the center field fence to cut Detroit's lead to 5-4.

When Eddie Murray followed with a line single to right, the joint was jumping. And the instant that Gary Roenicke unloaded a 400-foot blast that curved 20 feet foul, the throng let out a collective groan.

Surely, that was the last and best shot by a team that had been battling back all night after falling behind, 5-1, in the third. When Roenicke went out on a titanic pop, these almost-believers sat back in their seats.

They had not counted on the suffocating depth of the Oriole lineup with its five consecutive power bats. DeCinces worked the count to 1-1, then lashed at a high slider from loser Dave Tobik and sent it 400 feet into the Birds' pen.

For the O's, winners of seven in a row, 13 of 14 and 42 of 56 (.750) in the last two months, this was one of the mounting waves in a seemingly unstoppable hurricane of self confidence.

When Baltimore's starter, Mike Flanagan, was knocked out helped by three Bird errors in a three-run Detroit second the O's hardly seemed to notice. They have been coming from behind with ritual inevitability in recent weeks.

"There's so much electricity in our dugout, you can't believe it," said reliever Sammy Stewart, who pitched four shutout frames after Flanagan's departure. "The guys are just screaming that they want to kill the guy on the mound. They just wear him down."

Gradually, the Birds did, putting 14 on base against Pat Underwood and reliever Kip Young, as RBI hits by Singleton, Murray and May cut the margin to 5-3.

While the O's inched back, the Bird defense was superb In the fifth, Singleton made the Oriole throw of the season, gunning out fleet Ron LeFlore, perhaps the league's best base runner, when the speedster tried to score from second on a rope single at the right fielder.

The one-hop peg nipped LeFlore by millimeters. With men still at the corners, Stewart then coaxed a double play grounder out of cleanup man Lance Parrish.

As Steward, then winner Tippy Martinez, put six straight zeroes next to Detroit on the scoreboard, the O's kept pushing. Finally the Tigers broke.

"This team is no different than the '69 team that won 109 games . . . both have six guys who can win the game with a homer in the ninth, said Earl Weaver, in his wildest proclamation about his club thus far. "We have people capable of winning that many."

"The fans spooked Young and Tobik in the ninth," said DeCinces, as his teammates watched an instant replay of his blast on the locker room TV, then erupted again. "Tonight was just my turn to win a game," added DeCinces, who was summoned from the dugout for two hat tips. "Right now, we're the best team in baseball, no question."

Right now, they are, at the very least, the hottest and the most excited - no question. CAPTION: Picture, Red Sox' Dwight Evans is hit in arm by pickoff throw. Taking throw is Blue Jay John Mayberry. Evans left game. UPI