The Atlanta Braves made baseball history tonight, enjoyed a few minutes of riotous celebration in their own honor and promptly tried to clear their heads of it and get back to business.

By defeating the Cincinnati Reds, 4-2, before 37,268 howling fans, the Braves eclipsed the modern major league record for most wins to start a season. Oakland started last year with 11 straight to better the old record by one; tonight a new mark of 12 was established.

When it was over, admirers came pouring from the stands at Fulton County Stadium and mobbed pitcher Gene Garber, who retired the Reds in the ninth to secure the win. The Braves dallied only a moment before racing for the locker room where, in the words of rookie center fielder Brett Butler, "We went nuts for about a minute and a half, slapping high fives." Then someone shouted, "We can't stay undefeated if we don't win tomorrow," Butler said, and the Braves calmed down.

There was no champagne; just thoughts of the next day, next month and, in every Brave's mind, October. For the first time since 1969, they said to a man, the Braves intend to be playing in October.

It's a formidable, determined group, a blend of hungry people the world never heard of (Butler, double play duo Rafael Ramirez and Glenn Hubbard; catcher Bruce Benedict; outfielder Dale Murphy) and hungry people the world has heard a whole lot of (Chris Chambliss, who homered tonight, and Claudell Washington, who had a run-scoring triple).

And like the hungry A's, who went from their startling beginning last year to win the American League West title, the Braves have bigger goals than setting these records.

"This is nice, but we want the pennant," said owner Ted Turner.

"This streak has to carry over to winning a pennant," said team captain Bob Horner. "If we look back in September and we're not in it (pennant race), this won't mean anything."

"Defense, man, defense and pitching, that's us," said Washington.

Washington was sprawled on the floor of a makeshift interview room at game's end, his uniform coated with red infield clay from the head-first slide into third that capped his triple, which put the Braves ahead to stay.

In their streak the Braves' pitchers have given up an average of fewer than three runs per game. Tonight they did it again. Tonight the defense contributed four double plays and another sharp, inning-ending ground ball pickup by Ramirez. "When you get pitching and defense like that, you only need two or three runs to keep winning," said Washington.

As they have for the last three wins, the Braves tonight did it the hard way, coming from behind.

They fell behind, 2-0, in the second inning when starting pitcher Tommy Boggs couldn't find home plate. Boggs walked three men and gave Reds pitcher Frank Pastore and leadoff man Ed Milner pitches they hit for RBI singles. Manager Joe Torre called on reliever Steve Bedrosian with two out and the bases full.

Bedrosian needed only one pitch to get Cesar Cedeno to ground out, and he and Garber combined the rest of the way to allow six Reds hits, but not another run.

Meantime, Chambliss got one run back quickly with a mighty drive over the 385-foot mark in right field in the bottom of the second, and in the third Ramirez led off with a high fly that barely cleared the fence at the left field foul line to tie the score. Atlantans began cheering in earnest.

After two fly outs, Pastore walked Glenn Hubbard and Washington clobbered a fast ball that landed at the foot of the outfield fence at the 402-foot mark in dead center. Hubbard scrambled home and Washington sullied his uniform with the dive that left him dirty all evening. He scored shortly after, when Pastore threw a pitch in the dirt that went past Reds catcher Mike O'Berry.

It was all Atlanta needed.

Torre has only one nagging disaffection with the Braves, with whom he spent the bulk of his playing career. It's the fans. The Braves draw badly, and even tonight were 15,000 short of a sellout.

Worse than that, though, is the Georgia preoccupation with football.

"I just wish they wouldn't call me 'coach,' " said a laughing Torre.

Tonight, when the press ran out of questions for the most successful manager in baseball, there was the usual embarrassed shuffling of feet and waiting for some appropriate way to end the interview.

Finally a newsman said, "Thanks, Coach."