HOUSTON – By the time Carlos Beltran’s shot landed in Houston’s bullpen, this much was clear: At least baseball had one competitive playoff series still going.

Beltran did it again, homering in a record fifth straight postseason game and lifting the Astros over the St. Louis Cardinals 6-5 yesterday to even the NL championship series at 2-all.

Beltran’s tiebreaking shot in the seventh inning off Astros nemesis Julian Tavarez ensured the teams will go back to Busch Stadium to settle who goes to the World Series.

Meantime, there’s Game 5 tonight, with Brandon Backe starting for Houston against Woody Williams.

Sluggers again dominated. Not quite the way they did at Fenway Park, where the Yankees obliterated Boston 19-8 Saturday night for a 3-0 lead in the ALCS.

Albert Pujols homered for St. Louis, then came close to a go-ahead two-run homer in the ninth against Brad Lidge. But the ball was caught on the warning track, and the Astros closer struck out Scott Rolen for his second straight save.

Lance Berkman also homered for Houston, giving the teams a combined 19 home runs through only four games.

The excitable Tavarez upset his opponents last week by remarking, “We don’t look at the Houston Astros like this is a great team.”

Beltran exacted revenge with his bat. He reached down and golfed a 2-2 slider over the wall, sending the crowd at Minute Maid Park into a frenzy.

Beltran broke Jeffrey Leonard’s 1987 mark for consecutive postseason games with a home run, and matched Barry Bonds’ 2002 record for homers in a single postseason.

Tavarez further angered the Astros when he threw a fastball over the head of the next hitter, Jeff Bagwell. They exchanged words, plate umpire Mike Winters warned against further trouble, and play resumed without any problems.

Dan Wheeler wound up with the win, pitching one inning in relief.

With Roy Oswalt on the mound, the Astros really liked this pitching matchup. Yet the righty who led the league with 20 wins was far from his best – he hung around for six innings and didn’t strike out a single hitter for the first time since July 2003.

Oswalt went 2-0 against St. Louis this season, then won the clinching Game 5 of the first round at Atlanta. But he seemed too eager and too excited at the start and never found his rhythm.

Fortunately for the Astros, Jason Marquis wasn’t much better. Bumped down in the rotation after getting hit hard by Los Angeles in Game 2 of the opening round, he was in constant trouble against Houston.

Cardinals manager Tony La Russa kept looking for edges, and a couple of lineup shifts paid off. John Mabry started in place of left fielder Reggie Sanders and hit an RBI single, and rookie catcher Yadier Molina replaced Mike Matheny and threw out Craig Biggio trying to steal, and added a hit.

For the fourth straight game, the visiting team homered in the first inning. It was Pujols’s turn this time, and he lined a two-run shot into the Crawford boxes above the left-field wall.

Rolen followed with a double and later scored on Mabry’s single, marking the first time in 20 innings that St. Louis scored on something besides a home run.