PITTSBURGH -- Two long drives by Jason Bay and six excellent innings by their bullpen gave the Pittsburgh Pirates one of their infrequent victories over the Chicago Cubs, the team that torments them the most.

Bay hit a two-run home run before winning it in the 14th inning with a long single against a drawn-in outfield and the Pirates came back after squandering a late-innings lead to beat the Cubs 5-4 Saturday night.

The Pirates, who led 3-1 until the Cubs went ahead with three in the eighth against reliever Tyler Yates, tied it at 4 in the ninth on Luis Rivas' sacrifice fly against Kerry Wood. The Cubs' closer, working a night after he mopped up in the ninth inning of a 12-3 victory, blew his fourth save in 14 opportunities.

Freddy Sanchez reached when shortstop Ryan Theriot threw wildly on his grounder to start the 14th and moved up on Michael Wuertz's wild pitch. After Sanchez advanced to third on Rivas' grounder and Wuertz (0-1) intentionally walked Nate McLouth, Bay lofted a long fly close to the warning track in center to win it.

"It was my first RBI single of the year -- and it could have been a double if it hadn't been a walk-off (situation)," Bay said, referring to the scoring rule that counts all such game-winning hits as singles. "Regardless of how it happened, it's a win and I'm excited."

John Grabow (4-1) pitched three scoreless innings for the victory after Pirates closer Matt Capps also pitched three shutout innings.

"I said to him, 'What were the chances both of us would pitch three innings and get an at-bat?' " Capps said. "But the guys never quit, and if we continue to do that, it's going to be a good thing for us."

Manager John Russell said, "That's a situation where we can't give anything up and they didn't."

The Cubs, who have outscored the Pirates 85-46 while winning nine of 11 from them, tied it on Aramis Ramirez's two-run double and Kosuke Fukudome put them ahead 4-3 with a run-scoring single to center in the eighth -- delighting the thousands of Cubs fans whose cheers sometimes drowned out those of Pirates rooters in the crowd of 29,929.

But the Cubs lost for the first time in five games in Pittsburgh, where they have played games of 12, 15 and 14 innings this season.

"We've won some games against them, but they always play us close and we definitely don't see them on the schedule and think we're going to win," Theriot said. "They always play us tough."

So tough Cubs manager Lou Piniella, citing fatigue, declined to talk to reporters after the game.

Wood's botched save developed after he hit pinch-hitter Doug Mientkiewicz with a pitch and Xavier Nady singled to start the ninth. After Sanchez bunted the runners up, Rivas hit his sacrifice fly to medium-range right field.

"The bottom line is I've got to get the job done, learning curve or not," said Wood, a starter turned closer. "These games mean something and you've got to win those games, especially the way the offense came back and gave us the lead."

Until the Cubs rallied, Pirates left-hander Phil Dumatrait limited them to Geovany Soto's run-scoring double over 5 2/3 innings and Bay hit a two-run homer in the fourth and scored on Michaels' single in the sixth.

Dumatrait, a waiver wire pickup from Cincinnati, might have stayed in the game longer if Theriot hadn't begin the fifth by hitting a line drive about four inches above the pitcher's right knee, with the ball ricocheting to first baseman Adam LaRoche for the out. The ball left a nasty welt on Dumatrait's thigh.

Dumatrait shook off the injury, but walked two batters and allowed Soto's single to load the bases with two out and bring on reliever Franquelis Osoria, who retired Mark DeRosa on a called third strike.

Cubs starter Jason Marquis, who has beaten only the Pirates in nine starts this season and was trying to defeat them for a third time, gave up seven hits and three runs in 5 1/3 innings.

Bay, enjoying a comeback season after batting a career-low .247 with 21 homers last season, has hit 10 of his 12 homers in PNC Park. Going into this season, Bay had hit only 46 of his 118 career homers there.

Notes

• SS Jack Wilson (strained left calf), out since April 3, may rejoin the Pirates from a minor league rehabilitation assignment as early as Sunday. He is expected to play Tuesday at Cincinnati.
• Bay moved past Richie Hebner into 11th place with his 129th career homer for Pittsburgh. He has 130 career homers, hitting one for San Diego in 2003.
• Pirates C Raul Chavez picked Alfonso Soriano off second after he doubled to start the ninth.
• The Cubs were 26-1 when ahead entering the ninth.