Pittsburgh, PA (Sports Network) - Jason Bay drove in Chris Gomez with the game-winning run in the 11th inning as the Pittsburgh Pirates edged the Chicago Cubs, 6-5, in the finale of a three-game series at PNC Park.

Bay finished 2-for-5, while Luis Rivas homered twice for the Pirates, who took two of three in the set. Pittsburgh has won three of its last four after dropping its previous three games. Nate McLouth chipped in with three hits and an RBI and Xavier Nady hit a solo homer in the win.

Paul Maholm started and went eight innings, giving up five runs on eight hits in earning a no decision for the Pirates. Damaso Marte (4-0) got the win by pitching a scoreless 11th inning and striking out a pair.

Alfonso Soriano hit a two-run homer, while Aramis Ramirez had two hits and knocked in two for the Cubs, who have lost four of their last five.

Ted Lilly surrendered four runs on 10 hits, including three home runs. The veteran left-hander struck out two and walked a pair.

With the Cubs holding a 5-4 lead, Carlos Marmol was brought on for the ninth and retired Gomez to start the inning. However, Freddy Sanchez walked and was replaced by Brian Bixler. Following a Rivas strike out, McLouth hit a fly ball to the rim of the warning track in left, but Soriano, with his sunglasses up, lost the ball in the sun allowing Bixler to score the tying run. Nady then grounded out weakly to third and the game went into extra innings.

"When it went off the bat, it was very clear," Soriano said of the misplay in the ninth inning. "But when it fell into the sun, it was very tough to catch."

Neither team was able to score in the 10th and after Chicago failed in the top of the 11th, Pittsburgh capitalized off Jon Lieber (2-3) in the home half. Gomez got the inning started with a lead off single and took second when Bixler dropped a sac bunt. Rivas then struck out swinging and Lieber intentionally walked McLouth. Bay ended the game when he roped an 0-1 fastball down the left field line allowing Gomez to score with the winning run.

"I felt fairly comfortable at the plate early on, but I wasn't getting the results," Bay said. "I was getting close and it's nice to see some results. I've been feeling this way for a while. It's something I hope I can continue all year."

After Maholm retired the Cubs in order in the top of the first, Rivas' first homer of the season, a solo shot that just cleared the wall in left gave the Pirates the early advantage.

Nady's solo blast to left in the second put Pittsburgh up 2-0.

Chicago, however, came back with four in the top half of the third. Mark DeRosa got things started with a two-base hit and came around to score when Henry Blanco followed with a single to left. After Lilly struck out, Soriano launched the first pitch of the at bat over the field wall to give the visitors a 3-2 edge.

The Cubs tacked on another when Ryan Theriot drew a walk, advanced to third on Derrek Lee's ground-rule double and scored on Ramirez's groundout to short.

Rivas' solo homer in the bottom of the third, his second of the day, made it a 4-3 game.

Pittsburgh had a great chance in the fifth as it loaded the bases with one out, but Bay and Nady both flied out to center to end the frame.

Adam LaRoche led off the bottom of the sixth with a two-base hit and Jose Bautista followed with a run-scoring single that tied the game at 4-4. Ronny Paulino then drew a free pass, but Maholm grounded into a force out and Sanchez bounced into a 5-4-3 double play to end the inning.

Chicago reclaimed the lead in the eighth when Lee doubled with one out and scored on Ramirez's ground single up the middle, putting the Cubs ahead 5-4.