In a desperately crucial game, the goal of any baseball team is to achieve, or somehow stumble upon, a state of grace in which the club is mentally focused, physically committed and emotionally poised.

Icy and tough.

Maybe the best way to get in this condition, if the recent past offers a clue, is to embarrass yourself so badly that the thought of more humiliation is intolerable.

The Milwaukee Brewers know the feeling, particularly now that, after a 9-5 victory, the choke is on the other throat. That's why their joy this evening at their restored dignity was tempered by wariness at the thought of the California Angels' fury.

What the Baltimore Orioles almost did to mighty Milwaukee one week ago, the Brewers are on the verge of doing to the Angels.

After a rain-battered victory over the Angels this dreary afternoon, the Brewers are on the brink of making history in Sunday's fifth game of the American League championship series.

Since baseball began its playoffs in '69, 15 other teams have fallen behind two games to none, as the Brewers did this week in Anaheim. Not one has come back to reach the World Series. In fact, only the '72 Detroit Tigers, facing the Oakland A's, even managed to force a fifth game.

Now, after back-to-back wins in sudsy County Stadium, including this victory built on the heroics of mystery men Moose Haas and Mark Brouhard, the Brewers have a chance to complete one of baseball's finer comebacks when Pete Vuckovich faces California's Bruce Kison at 4:20 p.m. (EDT) in the finale.

Conversely, the Angels have the misfortune of being one defeat away from reviving the recurring nightmare of Gene Mauch, their manager -- the memory of his '64 Pholding Phillies. Long ago, they blew a pennant after it seemed as securely clinched as an Angel pennant did just two days ago.

For Milwaukee fans, the irony of their performance in the mist and muck today could hardly be sharper. Exactly one week ago, the True Blue Brew Crew was looking down the barrel of the worst last-week collapse in the history of 20th-century pennant races. Or, as Milwaukee General Manager Harry Dalton called it today, "A colossal flop."

After three defeats in 24 hours in Baltimore, the Brewers had to gather what remained of their shaken strength to win the division by beating the Orioles on the last day of the season. Now, it's the Brewers who have experienced the same sort of home-park exhilaration that inspired the Orioles in Memorial Stadium last Friday and Saturday.

Conversely, no team should know better than the Brewers how difficult it can be to complete such a remarkable comeback. "We're happy. . . but we're concerned," said Dalton. "The point will certainly be made to our people that last Sunday the Orioles probably couldn't help but feel that they couldn't lose." And Milwaukee pinned their ears back, 10-2.

Or, as philosopher Reggie Jackson said after this game, "Pitching is always the most important thing in a game like this . . . but, after that, it such seems like the team that wins is usually the team that has more to lose."

In this case, the potentially embarrassed Angels would be mocked and Mauched in defeat.

Milwaukee had three heroes in this miserable, chilly, thrice-delayed game that ended five hours, 25 minutes after its scheduled first pitch.

First comes starting pitcher Haas, who didn't allow a hit until two out in the sixth inning and who entered the eighth inning with a two-hitter and a 7-1 lead. That Manager Harvey Kuenn left him in for nearly five hours and 136 pitches -- the 136th an eighth-inning grand-slam home run by Don Baylor, who now has an AL divisional playoff record 10 RBI in this series -- was hardly Haas' fault.

Haas, the man who got bumped from the Brewers' rotation when Don Sutton arrived, had not started a game in 26 days. In fact, no sooner had Haas warmed up than steel-gray fog banks lowered into County Stadium, sheets of mist and rain pelted the park and his first pitch was delayed 104 minutes. However, Haas' gumption, a good low slider and a 25 mph wind blowing straight in from center field more than overcame his rustiness.

"I didn't know, nobody knew, how long or how well I would pitch," said Haas, who had a 6-0 lead before he allowed the first Angel hit -- a Fred Lynn RBI double in the sixth on Haas' 99th pitch.

If Haas, a credible 11-8 pitcher this season (4.47 ERA), was a mild surprise, then the Brewers' other star was a full-scale shocker. Little-known Mark Brouhard got to start in left field because former home run champion Ben Oglivie ran into the wall on Friday while not catching a fly ball.

Brouhard, whom the Angels didn't bother to protect in the '79 draft, had a season in one day. His highlight film and the game's were the same as he had a single, double and home run, a playoff series record four runs scored and three RBI.

In the second inning, Brouhard, unbelievably, went home-to-home on a grounder back past the pitcher; that simple RBI single turned into a three-run play as Lynn's throw to third hit a runner and rolled to the box seats, and Doug DeCinces, after retrieving the ball, threw it into the first-base box seats, almost parting the hair of American League President Lee MacPhail.

In the fourth, Brouhard hit into a fielder's choice, but still scored as part of a three-run inning built on two walks, two singles and two wild pitches.

In the sixth, Brouhard, who specialized in even-numbered innings, doubled off the glove of cursed third baseman DeCinces, who made two errors while playing with a broken nose and two black eyes; Brouhard then scored for the second time on a hit by Jim Gantner.

Finally, in the eighth, after Baylor had pulled the Angels back to 7-5, Brouhard iced this game with a two-run homer. Actually, he did it partially by accident. In an early at bat, he had botched a bunt and in that at bat he swung and missed at a hit-and-run. "I guess I didn't look too good bunting or hitting-and-running," said Brouhard, "so, they let me swing."

Fittingly, the last out of the game, as reliever Jim Slaton wrapped up his five-out save, was a routine fly right at Brouhard. He ran back. He stopped. He threw up his arms -- "I got it." Then, he trotted in. Then, he sprinted in. Finally, in total panic, he dove, fell on his face and made a grass-high catch.

"I forgot about the wind," he said.

The third, and unlikeliest, Brewer hero was Angels starter Tommy John. In his 10-out stay, John walked five men, four of whom scored, and made an playoff series record three wild pitches. The only place most of his ankle-high pitches might have been strikes would have been in a bowling tournament; only his gutter ball was sharp. Milwaukee managed just three singles off John, but that was only because they didn't have Ian Botham, the legendary cricketeer.

While the Brewers will have 50,000 on their side Sunday, all the Angels'll have will be, perhaps, the strongest emotion in team sport. Let Mauch, the man who wants and needs this exonerating victory the most, explain: "Milwaukee's point of view has got to change. How much looser could you be (than in the last two games)? Now, they're down to a one-game season. We'll see who can handle it better. Their thinking will be different tomorrow.

"There's a lot of difference between 'want to win' and 'have to win,' " said Mauch. "We're going to win. Because we have to."

It usually works that way. Except sometimes.