Adam LaRoche hit a grand slam among his two homers and the Pirates stalled the Dodgers' late-season surge with an eight-run seventh inning rally that keyed a 15-8 victory Wednesday night.

Ryan Doumit, who drove in four runs, hit a go-ahead, two-run homer as nine consecutive batters reached base in the seventh after reliever Scott Proctor retired the first two batters, only to be lifted. Los Angeles had bounced back to tie it in the top of the inning after once trailing 7-4.

"It was fun to break out in a game like that, especially against a team like that," Doumit said. "To finally have a game like this is fun."

It wasn't much fun for the NL West leaders.

The nightmarish seventh inning was one of the Dodgers' few blips during a late-season run in which they won 14 of 16, enabling them to gain nine games in the division standings in 19 days and open a 4 1/2-game lead over Arizona. The Diamondbacks played the Giants later Wednesday.

"It's a loss you have to put behind you," manager Joe Torre said. "We came back to tie it, and it looked good at that point (in the seventh), but we couldn't get to the eighth inning."

Doumit's 14th homer came off rookie left-hander Scott Elbert (0-1), who didn't retire any of the four batters he faced, and Andy LaRoche's two-run single - only his fourth hit in 35 at-bats - made it 11-7. Andy LaRoche, Adam's brother, was traded by the Dodgers during the three-team deal July 31 that sent Manny Ramirez to Los Angeles.

"He battled right there and smoked a ball and got a couple of RBIs, and that was pretty exciting for me," Adam LaRoche said. "He's trying and wanting to do something against his old buddies."

Torre defended lifting Proctor, saying he wanted Elbert to face Nate McLouth, who has all but three of his 26 homers against right-handers.

"I felt pretty good about that situation. We'd set up those line of hitters for Elbert and it just didn't work out," Torre said.

Pinch-hitters Doug Mientkiewicz and Jason Michaels also had run-scoring hits against Jason Johnson, and first baseman James Loney's two-run throwing error finished off Pittsburgh's biggest inning this season. The Pirates, losers of 30 of their previous 43, had scored eight runs or more in a game - much less an inning - only twice in 46 games.

The Pirates, already assured of a record-tying 16th consecutive losing season, were coming off one of their worst games of a bad season, a 6-2 defeat Tuesday in which they look lethargic and eager to end the season.

"We came back today and had some big hits and we kept pouring it on, and this was good," Adam LaRoche said. "It's something to build off and hopefully finish off with some wins."

John Grabow (6-3) got the victory despite giving up Angel Berroa's RBI double in the top of the seventh.

Adam LaRoche's third career grand slam put the Pirates ahead 7-4 in the fifth and followed his solo shot the inning before, with his two drives off Chad Billingsley giving him five RBIs. The LaRoches finished with seven RBIs between them. Billingsley failed to win his fourth in a row, allowing eight hits and seven runs in 4 2-3 innings.

"It wasn't good today," Billingsley said.

The Pirates' final 12 runs scored after there were two outs and nobody on base.

Adam LaRoche, as usual, is crowding most of his season's production into the final three months. After hitting below .200 for most of April and May, LaRoche has 16 of his 22 homers in his last 65 games. He is hitting .375 in September with eight doubles, four homers and 21 RBIs in 14 games.

The Dodgers outhit Pittsburgh 18-15, but ran themselves out of innings several times.

First baseman Nomar Garciaparra, playing in only his 50th game of an injury-interrupted season, reinjured his left knee while attempting to score from second on a two-out single in the fifth inning. Garciaparra pulled up between third and home in at attempt to get back to third, only to be tagged out.

"It could have been a lot worse," said Garciaparra, who didn't know how long he will be out.

Berroa was thrown out trying to stretch his double into a triple in the seventh.

Notes

Doumit's homer was his first at PNC Park since July 7. ... The loss was only the Dodgers' seventh in 29 games in Pittsburgh since PNC Park opened in 2001. ... Los Angeles outscored Pittsburgh 14-4 in the first two games of the four-game series. ... The Dodgers hadn't previously allowed more than six runs in an inning this season.