PITTSBURGH – The Pittsburgh Pirates keep falling behind so early and so often, it almost seems as if they are beginning every game with a three-run deficit. No wonder they looked like a much different team when they enjoyed a big first inning instead of giving one up.

Jason Bay hit a three-run homer in the first to get Pittsburgh off to an unaccustomed quick start, and the Pirates withstood Albert Pujols’ 10th homer in 14 games to beat the St. Louis Cardinals 12-4 Tuesday night.

Jeromy Burnitz also homered and drove in three for the Pirates, who shook off an occasionally ragged start by Oliver Perez (1-2) to beat the Cardinals for only the 11th time in 32 games in Pittsburgh. St. Louis had won six of seven there the last two seasons.

Bay followed infield singles by Chris Duffy and Jack Wilson against Jeff Suppan (0-2) to hit his third of the season, one of three Pirates homers in what suddenly is a hitter-friendly PNC Park. There have been 29 homers in nine games in what usually is a pitchers’ ballpark – a much faster pace than a year ago, when 140 homers were hit there in 81 games.

No doubt the 3-0 lead was welcomed by Perez, who gave up three runs and five hits in 6 2-3 innings to beat the Cardinals for the first time since July 22, 2003. The left-hander also got his first victory in his home park since defeating Washington last June 21, rebounding from a 13-5 loss to the Dodgers in his previous start.

“We’re a much different club when we get results like that,” manager Jim Tracy said.

The first inning has been the Pirates’ worst inning all season, as they trailed after the first in nine of their first 15 games and led only once. Four times, they allowed their opponent to score three runs in the first.

“We haven’t had a whole lot of these innings,” Duffy said. “It’s a lot easier to play the game that way. It’s tough to have to play from behind like that all the time.”

This time, the Pirates led 8-1 by the time Pujols matched Mark McGwire’s 1998 team record by hitting his 10th homer in April. Pujols’ long drive to left field was his fifth in three games, including a decisive two-run shot in St. Louis’ 2-1 victory Monday night.

“We’ve been down early a lot so, to get some runs early, we could relax a little bit,” Bay said. “We needed that as a team. It’s not easy when you’re hanging on every pitch in the seventh or eighth inning every night.”

Even after Jack Wilson’s fourth homer made it 9-2 in the fourth, Perez had to work out of a jam in the fifth. Aaron Miles doubled with one out and pitcher Josh Hancock and David Eckstein walked. So Taguchi singled to drive in a run and keep the bases loaded with Pujols coming up.

But Perez settled down to get Pujols and Scott Rolen on flyballs, and didn’t permit another hit before being pulled after walking Eckstein in the seventh.

“It was set up for us, but he made the pitches to get out of it,” manager Tony La Russa said. “It’s why you keep playing, sometimes you have one of those chances and you break through and, suddenly, you have a two- or three-run game.”

Asked about having about 1,100 feet worth of long fly ball outs in that inning, La Russa said, “Yeah, but they had about 3,100 feet worth of hits.”

Perez had an eventful season against the Cardinals a year ago, missing nearly months of the season after breaking a toe while angrily kicking a laundry cart in St. Louis on June 26. Once he returned, he lasted only 1 2-3 innings in a Sept. 14 start in which he was ejected for hitting Hector Luna with a pitch.

“It was important for me to pitch well in this game,” Perez said. “Last year was a tough year for me.”

Suppan had been 6-1 with a 3.09 ERA against the Pirates, but lasted only two-plus innings while giving up eight runs and eight hits, five for extra bases.

“Some of these games, it’s hard to come up with an explanation,” Suppan said. “They were able to capitalize on my mistakes and put together some good at-bats, and I didn’t make pitches.”