The Cubs, who began the day with a 1 1/2-game lead over Milwaukee, hit four homers and withstood a shaky start from Jason Marquis to send the Pirates to their seventh straight loss.

The Brewers, who played Friday night at Atlanta, had 10 games remaining while the Cubs have eight.

Ramirez hit a three-run homer in the first off Paul Maholm. He delivered another three-run shot, his 25th homer of the season, off Franquelis Osoria (0-2) to break a 7-7 tie in the sixth. It came right after Pirates' second baseman Freddy Sanchez dropped a flip on a perfect double-play ball.

With Alfonso Soriano at first and one out, Derrek Lee hit a hard grounder to short, but Sanchez couldn't catch the throw from Matt Kata, that could have led to the side being retired. Instead, Ramirez capitalized on the miscue and put the Cubs ahead.

Two batters later, Geovany Soto hit a two-run homer off John Grabow, and the Cubs had a five-run lead.

Soriano hit his 29th homer leading off the bottom of the first. The Cubs added another run in the seventh when Lee had an RBI single after the Pirates' third error of the game. Ramirez nearly followed with his third homer of the game, flying out to the wall.

Scott Eyre (2-1) pitched the top of the sixth for the win.

With the wind blowing out at 12 to 21 mph on a humid 85-degree day, crazy things were bound to happen at Wrigley Field - and they did.

By the bottom of the third inning, both starters had been driven out, the game was tied at 7 and the teams had already combined for 19 hits.

Maholm, who entered the game with a 4-0 career record against the Cubs, including 2-0 this season, had been routed in his previous start, giving up 11 hits and 10 runs to the Astros last Sunday in just 2 2-3 innings.

This time he didn't make it that far, going two-plus innings and surrendering 10 hits and seven runs, six earned.

But Marquis had just as bad a day. He gave up eight hits and seven runs in 2 2-3 innings.

Marquis got off to a shaky start in the first, giving up a leadoff single to Nyjer Morgan, two walks and two stolen bases. All the Pirates could manage after loading the bases was Xavier Nady's RBI fielder's choice grounder for a 1-0 lead. The Cubs then responded with four in the bottom half on the homers by Soriano and Ramirez.

Cezar Izturis' two-out RBI triple in a five-run third put the Pirates ahead 6-5 and finished Marquis.

Nate McLouth's single, a double by Adam LaRoche, an RBI grounder from Nady, a run-scoring double down the third base line by Jose Bautista and an RBI single up the middle by Paulino tied the game. Izturis, traded to Pittsburgh from Chicago on July 19, then hit a ball into the right field corner for three bases.

Will Ohman relieved and Maholm popped a bunt over his head and behind the mound for an RBI single that made it 7-5.

But the Cubs opened the bottom of the inning with three straight singles - the third by Ryan Theriot was off the wall in left but Soto was held at third- to load the bases. Pinch-hitter Ronny Cedeno delivered an RBI single to make it 7-6 and finish Maholm, leaving the bases full because Craig Monroe was also given the halt sign by third base coach Mike Quade.

Osoria got Soriano to pop up and struck out DeRosa before throwing a wild pitch that allowed Monroe to score the tying run.

Notes: It was Maholm's shortest outing of the season. It was Marquis' second shortest. He lasted 1 2-3 innings against Atlanta on June 9 ... Izturis had irritation in his right elbow and was replaced at short by Kata to start the bottom of the fourth. ... Nady hit a solo home run off Ryan Dempster in the ninth.