Already 4-for-4 on the day, Luke Scott stepped up in the bottom of the ninth inning with two runs already in and the go-ahead run on second base. Scott ripped a 1-0 pitch in the right-center field gap to win the game and collect his fifth hit of the day.
The Cubs move to 18-14 with the win.
Mark Buehrle turned in another quality start for the Cubs, going 6.1 innings and allowing just six hits and two earned runs before giving way to the bullpen. However, Pittsburgh's Joe Mays was able to match Buehrle pitch-by-pitch, throwing seven quality innings of his own.
With the score tied 3-3 in the top of the ninth inning, Kevin Youkilis thought he had put the Pirates up for good with a two-run homerun off of Cubs' reliever Matt Thornton, but Chicago was able to rally back in the bottom of the inning and give Thornton the win (1-0).
Dmitri Young led off the home half of the ninth by reaching base on an error and Chris Barnwell had doubled to put the tying runs in scoring position. Chris Burke later tied the game with a double of his own before scoring on Scott's hit.