updated 12:26 a.m. ET Aug. 29, 2008

CHICAGO - On his 65th birthday, Lou Piniella found himself in the middle of a noisy celebration. He can thank Aramis Ramirez for stirring up the party.

Ramirez hit a grand slam in the eighth inning Thursday night as the surging Chicago Cubs rallied for five runs to beat the Philadelphia Phillies 6-4 for their sixth straight win.

“What a great come-from-behind win. Just a great win. I mean, exciting,” Piniella said. “This place really got loud. ... I don’t know if it was the loudest I’ve heard it, but let me tell you what, it was loud.”

Wrigley Field wasn’t rocking so much through the first seven innings. Philadelphia lefty Cole Hamels was cooling off the Cubs, allowing just a run and five hits.

But the Phillies’ bullpen, which failed to hold an eighth-inning lead Wednesday night in a tough loss to the Mets, faltered again and a 4-1 lead evaporated.

The surging Cubs moved to 34 games over .500. Ramirez sent the roaring 40,362 fans into a tizzy when he drove reliever Chad Durbin’s pitch into the center field bleachers to complete the comeback.

“I mean I’ve been able to do that since I was in the minor leagues,” Ramirez said. “I’ve always been able to drive in runs, it’s something I’m proud of and I like to be in that situation late in the game.”

The game marked the first time instant replay was available for boundary home run calls, but it wasn’t used.

Reliever Ryan Madson gave up three straight hits to start the bottom of the eighth. Pinch-hitter Mike Fontenot homered leading off to make it 4-2, Alfonso Soriano doubled and moved to third on Ryan Theriot’s single.

Durbin (5-3) relieved and walked Derrek Lee to load the bases with no outs. Ramirez then hit a 1-0 pitch deep into the seats — Philadelphia center fielder Shane Victorino hardly moved as the ball left the bat — to give the Cubs the lead with his 24th homer.

“(Fontenot) hit a homer and all of a sudden it’s a two-run game and we got the top of our lineup coming. Soriano got on base and Theriot got on base. ... We got a good team,” Ramirez said.

With the loss, the Phillies dropped a full game behind the idle Mets in the NL East. The Cubs lead Milwaukee by 6½ in the NL Central.

“We shouldn’t be going through this. This is our time to hold these leads and it’s our job. We’re not getting it done right now,” Madson said.

Durbin was just as disappointed.

“Yeah, to think about how well Cole threw the ball and how well our guys put at-bats up against Dempster, it’s a tough one,” he said.

Cubs starter Ryan Dempster, who’d pitched out of trouble all game, gave up a leadoff double to Jayson Werth in the sixth, walked Pedro Feliz and then surrendered a go-ahead RBI single to No. 8 hitter Carlos Ruiz. Hamels sacrificed, Jimmy Rollins hit a sacrifice fly and Chase Utley followed with an RBI single, his third hit of the game, to put the Phils up 4-1.

But the Phillies couldn’t hold it.

“That was a situation where we couldn’t get people out. Actually the last game and most of the last games that we’ve lost, that’s kind of how it’s been,” Phillies manager Charlie Manuel said.

Bob Howry (6-4) pitched the eighth for the win. Kerry Wood gave up a leadoff single to Rollins in the ninth and a long warning track fly ball to Utley before getting his 28th save in 33 chances.

The Cubs tied the game 1-1 in the fifth when Kosuke Fukudome beat out a single behind second and Mark DeRosa drove a 1-2 pitch into the right-field corner for a run-scoring triple.

The Phils got to Dempster for a run in the first but left the bases loaded. Utley doubled, moved on a grounder and following a walk to Ryan Howard and scored on Victorino’s single. But after walking Werth to load the bases, Dempster fanned Feliz.

Philadelphia had second and third in the fifth after an Utley single and double by Howard but this time Dempster struck out Victorino.

Slide show   Week in Sports Pictures Flying on the hardwood, racing on the rink, getting physical on the gridiron, and much more. more photos

Notes: Phillies LHP Scott Eyre returned to Wrigley Field for the first time since being designated for assignment by the Cubs on August 5. ... Phillies starting pitcher Joe Blanton will face an ex-Oakland A’s teammate on Friday when the Cubs send Rich Harden to the mound. The pitchers, who were both traded in July, chatted behind the batting cage before the game. ... Ramirez now has 99 RBIs. He already has five 100-RBI seasons in his career. He also has eight career grand slams.

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