From Joaquin Andujar's music box came a reenactment of an A-bomb explosion. Either that or it was the Astro theme song, because soon enough the air was filled not only with champagne spray but also with words loud enough to knock down buildings. "Here come the Astros," the music box roared, "floating with desire." Yea, yea, yea. "Here come the Astros, breathing orange fire."

Gershwin, it ain't. But the way the Astros beat the Dodgers today, 7-1, the music fit the deed. These Astros were aflame in a playoff game for the National League West championship, breathing the same base-running fire they used all season to win the first championship for a franchise that began 19 years ago as the Colt 45s.

Art Howe, a journeyman hitter who had never been on a championship team anywhere, hit a two-run homer in the third inning and produced two more runs with a bases-loaded single that gave the Astros a 7-0 lead in the fourth.

Joe Niekro, a journeyman pitcher who has never been on a pennant-winning team anywhere, allowed the Dodgers only six hits off his confounding knuckleball to mark up his 20th victory of the year.

They were the obvious heroes as the Astros finally won a game here. Three games ahead with three to play, the Astros gave away three straight to the Dodgers over the weekend. Would this be the Houston team remembered as an Astro naught? But come today's playoff game, the Astros were the team that won 92 regular-season games and deserves to start the championship series Tuesday night against Philadelphia, the best in the East.

And they were the real Astros today because of Terry Puhl.

The Astro leadoff man breathed a whole bunch of that strange orange fire.

What he did was run like crazy. After flying from first to third on a little single in the first inning, he should have stayed where he was on a grounder to the third baseman. Instead, he came home. Silly fellow. Out by a mile, of course. Until he knocked the ball out of the catcher's hand with a hard slide. "Holy cow, I'm safe," thought a fairly amazed Puhl.

In the fourth, Puhl bunted for a single. And then stole second. And then stole third. By then the Dodger catcher, Joe Ferguson, didn't even try to throw him out. This guy Puhl was getting to be a pain.

Well, such stuff is catching, and pretty soon the Astros had those sunburst uniforms flying around the bases in blatant humiliation of the crippled, limping Dodgers.

It got so bad that Houston catcher Alan Ashby, no sprinter, tried to score from first on a double in the third inning. He, too, was out by a mile. And this time Ferguson not only blocked Ashby from the plate, he added a little knee-in-the-chest flourish of frustration as he stepped over the fallen runner.

Such indelicacy brought the Astros en masse charging from their dugout, looking for a good nationally televised brawl in defense of their offended comrade. And here came the Dodgers, too, even streaming out of the bullpen in left field.

Everyone got on camera and several threatening glares were exchanged. No punches were thrown.

Anyway, after 3 1/2 innings, the Astros had a 7-0 lead, and trend-watchers noted that the pattern of the first three games here was reversed today.

The Dodgers won those games with a formula that called for one home run and one gift run contributed by faulty Houston fielding. All the games were one-runners (indeed, these teams' last seven meetings had been decided by one run, the Dodgers winning five times).

But today the Astros had the home run, Howe's 10th of the season, and they were the benificiaries of sloppy Dodger fielding in the first inning.

Puhl reached base when second baseman Davey Lopes kicked away a simple ground ball. And Puhl scored when Ferguson, with plenty of time to get hold of everything important, dropped the ball.

While Howe's third-inning homer over the 385-foot sign in the left center -- a long out in the Astrodome -- gave the Astros a 4-0 lead, they left the Dodgers for dead in front of their 51,127 lovey-dovey fans with a fourth-inning rally that epitomized this fire-breathing outfit.

The Astros scored three runs on four walks, two stolen bases, a bunt single, a sacrifice fly and a two-run single so sorry that Howe joked about it.

"It was a broken bat up the middle," he said. "I hit it soft so that Joe Morgan, who's got that bad knee, could be sure to get around from second. If I hit it too hard, he has to wait at third."

Against this squadron of mosquitoes, the Dodger starting pitcher, a $3 million free agent named Dave Goltz, was helpless. Before the inning ended, the Dodgers tried two more pitchers in an effort to make these Astros go away.

What the Dodgers couldn't do, their fans almost did. They made the Astros disappear. With their heroes now trailing, 7-1, after Rick Monday's single drove in Dusty Baker in the fourth inning, some restless fans in left field threw ice, apples, oranges and toilet paper onto the field. The chief umpire, Doug Harvey, called the Astros off the field while he warned the patrons the game could be forfeited if such behavior continued.

Ahead, 7-1, the Astros could win with Jimmy Carter pitching underhanded. With Niekro on the form that has won 41 games the last two seasons, the Dodgers managed two hits in an inning only once. Their best chance at a miracle came in the sixth inning when they loaded the bases on a walk, Ferguson's half-hit single and a strikeout so good the knuckleball flew past catcher Ashby.

Niekro and the Astros escaped unharmed when Derrel Thomas hit a soft liner to center fielder Cedeno.

"We were looking for a miracle, to win four straight," said the Dodger manager, Tommy Lasorda. "We just came a little short. I guess the Big Dodger in the Sky didn't want it."