McClain's second homer this season gave San Francisco a 6-4 lead with two outs in the bottom of the inning. Like McClain, Pablo Sandoval had two hits and two RBI.

One of Rich Aurilia's two hits was a fourth-inning solo homer. Nate Schierholtz had two hits, one an eighth-inning solo homer, while Bengie Molina added three hits for the Giants, who had lost seven of nine.

The winning pitcher was reliever Geno Espineli (2-0).

Closer Brian Wilson recorded his 37th save despite giving up a run in the ninth.

Pittsburgh's Freddy Sanchez had four hits and two RBI. Nate McLouth had three hits and two RBI.

Andy LaRoche had three hits and Adam LaRoche two for the Pirates, who have dropped seven of 10.

The losing pitcher was Denny Bautista (4-2).