PHOENIX -- As Conor Jackson's two-run single bounced through Milwaukee's drawn-in infield, the Arizona Diamondbacks poured out of their dugout as if they had won a title.

All they had really done was reach .500. But it felt like a monumental achievement for the slumping NL West leaders.

In one of the more improbable victories in team history, the Diamondbacks overcame a five-run deficit in the ninth inning to defeat the Brewers 6-5 on Thursday. After being shut out for eight innings, the Diamondbacks sent seven men to the plate in the ninth, and every one reached base.

"Hopefully this will kind of spark us and get us going," said Chad Tracy, whose three-run, pinch-hit double was pivotal. "That looked like the old Diamondbacks right there, battling back and never giving up."

The victory lifted the Diamondbacks to 43-43 and kept them 1½ games ahead of the Los Angeles Dodgers.

Afterward, they still weren't quite sure how they had done it.

"I was almost in shock, basically," Arizona manager Bob Melvin said. "We played possum for eight innings, and in the ninth inning we surprised them. Don't ask me."

For the Brewers, the loss put an agonizing end on a 5-5 road trip to Atlanta, Minnesota and Arizona.

"It was a very tough loss for us today, especially going into the ninth inning 5-0," said closer Salomon Torres (4-2), who blew his third save in 18 chances. "It appears to be the deal was sealed, but apparently it wasn't."

The rally began like a dripping faucet but quickly became a flood.

Three Arizona reserves -- Robby Hammock, Chris Burke and Augie Ojeda -- breathed life into a seemingly moribund team. Hammock led off with a single against reliever Guillermo Mota. Burke drew a walk and then Ojeda loaded the bases with a scratch single to second.

The Chase Field crowd of 23,842, or what was left of it, was suddenly on its feet and cheering. Lefty Brian Shouse came on to face Tracy, batting for the pitcher.

Tracy was hitless in seven at-bats against left-handers this season, but Melvin had no righties on his bench. Tracy said he knew he'd have trouble with Shouse's slider, so he went up looking for a fastball.

Shouse delivered one on his first pitch, and Tracy belted it into the gap in right-center to clear the bases and make it 5-3.

"Typically, he's started me out in the past with fastballs, and he gave me exactly what I was looking for, and I put a good swing on it," Tracy said.

Brewers manager Ned Yost summoned Torres, who gave up a bloop single to Justin Upton, putting runners at the corners.

Orlando Hudson's double down the left-field line made it 5-4, but the crowd groaned when Upton ignored third-base coach Chip Hale's green light and stopped at third.

The baserunning blunder didn't matter. With Upton at third and Hudson on second, the Brewers brought the infield in. Jackson bounced a single up the middle and a party broke out at home plate.

"It's just a situation you always dream of being in as a kid," Jackson said. "You want to drive in the winning run, win the game and be the hero."

Torres didn't feel heroic. He had converted 14 consecutive save opportunities since taking over the closer job, but he'd rather forget this outing.

"I'm sure I'm going to digest the whole thing later tonight on the plane," Torres said. "It's just one of those things you have to shake off and be ready to go at it next time."

While the Diamondbacks mobbed each other, the Brewers trudged off the field in shock.

"It's just one of those innings," Yost said.

Arizona's rally wasted a big day by Milwaukee shortstop J.J. Hardy, who homered, doubled twice and singled. The four hits matched a career high.

Hardy has hit in a team-high 15 consecutive games, and he went 11-for-18 with three home runs and six RBI in the four-game series with Arizona.

The Diamondbacks' rally cost Brewers starter Manny Parra his seventh consecutive victory. Parra blanked the Diamondbacks on four hits over six innings.

Parra has not allowed a run in three of his last four starts. And he has given up one earned run in 13 innings against Arizona this season.

Leo Rosales (1-0) pitched the ninth for Arizona for his first major league victory.

Notes

• Arizona's record is overcoming a six-run deficit.
Arizona RHP Dan Haren, the NL pitcher of the month for June, will start the opener of a three-game series against San Diego on Friday night. Haren shut out the Padres over seven innings of his only start against them, a 9-0 victory on April 18.
The Brewers lost for the 19th time this season in a game they led.