In baseball, it's possible to win a divisional pennant and have no idea how you did it. The jubilant Philadelphia Phillies are proof.

In Busch Stadium today, the Phillies scored five runs in the ninth inning off St. Louis Cardinals ace Bruce Sutter to come from behind and win, 9-6, for their ninth straight triumph--the longest Phillies winning streak since 1969.

"It's a cliche, but it's momentum," beamed 59-year-old Manager Paul Owens, who risked his reputation as a front-office wizard by coming down to the field level in midseason to join his slumping troops in battle.

"I can't remember when I felt younger," said Owens, whose Phillies blighted the hopes of Montreal with a doubleheader sweep on Thursday night, then saw Steve Carlton win his 300th on Friday. "You say, 'Boy, I hope this doesn't stop tomorrow morning.' It's like being on a roll with the dice at Atlantic City. You can't conceive of losing.

"And I don't care what anybody says, we all watch the scoreboard. I know when our score went up in Montreal the Pirates had to think, 'Those damn Phillies won again.' "

When the Phillies began this binge, they were tied with Pittsburgh for the National League East lead. Montreal was just a half-game behind and the Cardinals were 2 1/2 back. Now, almost before the impact of the Phils' streak has been realized, the defending world champion Cardinals have been eliminated, the Expos are six games behind and only the Pirates, who won, 1-0, over Montreal to stay three games back, have a prayer.

"In that ninth inning, if you were playing a computerized baseball game and you punched in what you needed, if couldn't have been more perfect," said Mike Schmidt, who finished the rally with a two-run homer. "Everything baseball calls for, we did like a textbook."

Indeed, that final inning showed a team both playing well and praying well. After scoring four runs in the first inning, the Phillies spent the rest of the afternoon frittering away their margin until, in the eighth, the Cardinals pushed ahead, 5-4. With Sutter on the mound, the Phillies' streak looked sickly.

Leadoff pinch-hitter Von Hayes, down on the count 0-2, chopped a grounder over Sutter into center. Pinch-hitter Len Matuszek hit what should have been a single to left to put men at the corners, but left fielder Andy Van Slyke misjudged the turf hop and had the ball tick off his glove and go to the fence for a game-tying double that knocked the wind out of the Cardinals.

Another pinch-hitter, Bobby Dernier, failed to sacrifice twice, but, once again, the Phillies pulled a rabbit out of the hat as Dernier managed a grounder to second base, advancing Matuszek. When second baseman Jeff Doyle threw the ball in the dirt past first into the Cardinals dugout, the go-ahead Phillies run trotted home and the Cards' will to fight died.

After Joe Morgan gave himself up with a ground out to first, advancing Dernier to third, old Pete Rose laid down a gorgeous suicide squeeze bunt for what proved to be the winning run. The Cardinals could only let his dead fish roll, hoping it would turn foul. The ball stopped next to third base, fair by a foot.

Sutter went limp and Schmidt went deep, increasing the Phillies' lead to 9-5 and making a St. Louis run in the ninth immaterial.

"In the last couple of weeks I've seen so many innings like today," said Rose. "Hell, we've been waiting for this to happen for four months."

Less than four weeks ago, the Phils were only three games over .500 and in such a state of frustration and self-disgust that Schmidt lambasted Owens, saying that nobody had any idea when, where or if he would be playing the next night.

At one point, Owens made 16 different lineups for 16 games, and the charge seemed apt that the Philadelphia batting order was determined by lot.

Owens responded by picking up the Phillies stat sheet and pointing at the sub-.250 batting averages of gentlemen of large salary and small production, like Rose, Morgan, Bo Diaz, Tony Perez and even Schmidt.

Now, for no reason that any sage can divine, the Phillies are the hottest team in the National League. They've won 21 of 27 and 16 of 19 to come from high-paid disrepute to pennant-race glory.

Owens attributes the turnaround to a kind of Baltimore syndrome. He volunteers that he's adopted methods similar to those of Earl Weaver, platooning at several positions, trying to get more players involved.

"I think they finally realized that, to win, everybody has to participate. In Baltimore, they all have the feeling that they're part of the team effort. We didn't have that. Now, I think we do . . . Also, my club isn't tired coming down the stretch because the older players have been rested."

"Playing baseball in the last weeks of the season really teaches you something about how the sport should be approached. It's a totally different game," said Schmidt. "I don't know if its humanly possible to play like this for 162 games. Why is the intensity on this team so much higher now? Earlier in the season, there's not that sense of pressure. The weight of the games isn't there. These are the same people. I don't know what's brought the best out in us.

"I'm just going to stay in this coma . . . and I hope the rest of us do, too."

For many of the most famous Phils--particularly Rose, Morgan and Perez, who have all been benched and disregarded more than at any time in their careers--this has been the hardest of summers. Now, they're coming through.

For instance, Morgan, who in one slump got only 14 hits in 40 days, got 14 hits in his previous four games before today.

Morgan, after a season of benchings and general indignities, decided to stop caring. "I don't have to prove anything to anybody," he said today. "I went through a few mental changes . . . I got some things off my chest about three weeks ago and just generally said, 'The hell with it.' "

And when Morgan stopped worrying?

"Oh, naturally, I started playing relaxed, got red hot and now I'm in the lineup all the damn time," said Morgan, laughing at himself and shrugging.