With a two-run sixth inning, the Pittsburgh Pirates broke a 4-4 tie, and the bullpen protected the lead as the Pirates (62-44) defeated the Chicago Cubs (58-48) 7-5 Wednesday night. With the win, the Pirates earn a split of the two-game series and push their lead over the Cubs back up to four games in the N.L. Wild Card race with the San Francisco Giants sitting in between at 3 1/2 games out.

Gregory Polanco and Andrew McCutchen drove in the clutch game-winning runs in the bottom of the sixth. Francisco Cervelli and Michael Morse started the rally, each with one-out singles. Polanco doubled home Cervelli, and McCutchen drove in Morse's pinch runner, Sean Rodriguez, with a line-drive sacrifice fly to right. After the two-run rally, Pittsburgh held a 6-4 lead.

The Pirates added an insurance run in the seventh on Rodriguez's RBI single that scored Cervelli. 

No Pirate had more than two hits, but nine players combined for 12 hits on the night with six of them driving in runs. 

The Cubs threathend in the ninth, getting two men on and the tying run at the plate. Addison Russell's RBI groundout brought in one, but the Cubs could not score any more. 

Pittsburgh scored immediately as Polanco cranked his first career lead-off home run (5) (video). They added another run two outs later on Pedro Alvarez's RBI single with the bases loaded that brought in McCutchen. Aramis Ramirez tried to score from second on the hit, but Chris Denofria gunned him down at the plate to retire the side.

McCutchen homered (16) over the center-field wall in the third to make it 3-0 (video), and Ramirez drove in Starling Marte with a single in the sixth to make it 4-1.

The Cubs got a run in the top of the fourth on Anthony Rizzo's sacrifice fly. Two sixth-inning home runs -- a two-run fence scraper from Kyle Schwarber (5) and a solo blast from Rizzo (21) tied the game at 4-4. The Cubs then loaded the bases but could not score again. Pittsburgh broke it open in the bottom half of the inning.

Antonio Bastardo (W: 3-1, 3.82 ERA) won it in relief with 1/3 of an inning, pitching to one batter. He got pinch hitter Chris Coghlan to ground out to end the sixth. Three more Pirates relievers each pitched an inning with Mark Melancon (S: 34) closing it out after allowing a run. He struck out Dexter Fowler, the potential tying run, to end it.

Travis Wood (L: 5-4, 4.58) allowed two runs on three hits while getting only one man out in the sixth. Starter Dan Haren allowed four runs (three earned) on seven hits, two of them home runs, while walking two and striking out three in his first start with the Cubs.

On Thursday, the Cubs return to Wrigley Field to start a four-game series with the Giants that will determine who owns the second wild card spot as it ends on Sunday. Pittsburgh, meanwhile, takes Thursday off before welcoming the N.L. West-leading Los Angeles Dodgers to PNC Park. Both series will have divisional and wild-card race implications.