PITTSBURGH, April 19 (UPI) -- Mark Grudzielanek's RBI single ignited a five-run 10th inning Saturday night as the Chicago Cubs defeated the Pittsburgh Pirates, 6-1, for their fifth straight victory.
Nursing a 1-0 lead, Cubs manager Dusty Baker gave Mark Prior (3-1) a chance to finish the game himself, but the Pirates pushed across the tying run in the bottom of the ninth.
Jason Kendall reached on an infield hit and moved up on Matt Stairs' groundout. After Aramis Ramirez walked, both runners advanced on a wild pitch.
The Pirates tied it on Randall Simon's groundout, but Prior stranded the winning run at third by striking out Reggie Sanders.
Given a reprieve, Chicago went to work against the Pirates' bullpen in the 10th. Mike Williams took over after Scott Sauerbeck (0-1) gave up a leadoff single to Damian Miller but was ineffective.
After walking Eric Karros, Williams gave up four straight hits. Alex Gonzalez followed Grudzielanek with an RBI double before Sammy Sosa's two-run single made it 5-1. Ramon Martinez capped the uprising with a sacrifice fly.
Coming off his first loss, Prior allowed one run and six hits in nine innings with two walks and six strikeouts.
The Cubs, who were held to two hits before the 10th, took a 1-0 lead in the fourth as Moises Alou was hit by a pitch with two outs and scored on rookie Hee Seop Choi's double.
Joe Borowski pitched a perfect 10th for Chicago.
