ATLANTA – It took 43 years, but the Houston Astros are finally postseason winners.

Carlos Beltran hit two more homers and drove in five runs, while original Killer B’s Craig Biggio and Jeff Bagwell chipped in during a five-run seventh inning that carried the Astros to a 12-3 rout of the Atlanta Braves last night in the deciding Game 5 of their first round NL playoff series.

The Astros snapped an 0-for-7 record of futility in the playoffs against their longtime nemesis. The Braves eliminated Houston in 1997, ’99 and ’01, but they couldn’t escape their own postseason demons this time.

Atlanta has lost Game 5 of the division series three years in a row – all in Atlanta. The second-largest crowd in franchise history, 54,068, saw another familiar ending. The team that proudly displays 13 straight division titles still has only one World Series to show for it. This one was especially dismal, equaling the worst postseason loss in franchise history.

Next up for the wild-card Astros is a matchup against Central Division rival St. Louis in the NL championship series starting tomorrow night at Busch Stadium.

Houston jumped ahead 3-0 on Braves starter Jaret Wright, scoring two in the second and adding to their lead when Beltran homered into the Atlanta bullpen in the third.

The Braves had the big crowd roaring in the fifth. Rafael Furcal led off with a homer against Roy Oswalt, and Johnny Estrada hit another into the seats with two outs, pulling Atlanta to 3-2.

But Beltran, acquired from Kansas City in June, quickly turned the tide back in Houston’s favor. He started the sixth with a towering drive off Wright that just cleared the right-field wall.

The Astros were back in control. The Braves were done.

Oswalt, pitching on three days’ rest for only the second time this season, made it through five innings. He threw 111 pitches and the Braves stranded runners in every inning, seven in all against the Houston starter.

Houston poured it on in the seventh after Atlanta summoned Chris Reitsma from the bullpen. With two outs, Biggio lined an RBI single to right and wound up at third when the throw home skipped away from Estrada. Beltran followed with another single, driving in his third run of the game, before Bagwell launched a mammoth drive to left-center for a two-run homer.

Reitsma stood beside the mound, staring at the ground. Manager Bobby Cox emerged from the dugout to make a pitching change, drawing a mock cheer from the big crowd – much of which then headed for the exits.

Before the seventh was done, Jeff Kent also drove in a run off Tom Martin, giving the Astros a 9-2 lead.

Bagwell and Biggio, who took much of the blame for Houston’s futility through the years, finally silenced their critics. Biggio was 8-of-20 (.400) with a homer and four RBIs in the series. Bagwell was 7-of-22 (.318) with two homers and five RBI.

But no one was better than the newest B. Beltran was 10-of-22 (.455) with four homers and eight RBIs in the five-game series.

The Astros underachieved much of the season. Phil Garner took over as manager at the All-Star break, and Houston had to win 36 of its last 46 games just to get the wild card.

Not a bad formula, actually. Last year, the Florida Marlins fired their manager during the season, got into the playoffs as a wild card and went on beat the Yankees in the World Series.

Wright gave up only 11 homers in 32 starts during the regular season, but he couldn’t keep the ball in the park during his two postseason starts – especially against Beltran.

The Astros outfielder went 5-for-6 with three homers against Wright. Overall, Beltran broke the Houston record for postseason homers.

In a poignant note, the record was formerly held by Ken Caminiti, who hit three in an opening-round loss to the Braves in 1999. Caminiti, who spent 10 seasons with the Astros, died Sunday of an apparent heart attack at age 41.

The news hit Caminiti’s former teammates – Biggio and Bagwell – especially hard. “I guess the best thing we can do today for him is just go out and play well,” Biggio said before the game.

Furcal had a huge series for the Braves, with eight hits and two homers. He had plenty of incentive, facing a 21-day jail sentence after being arrested for the second time on DUI charges.

The judge set the sentence to begin the day after the Braves’ season ended. Furcal will have to report to jail today.