Buster Posey hit a pair of home runs – including his first career grand slam – to help Tim Lincecum avoid a career-worst third straight loss as the San Francisco Giants pounded the Milwaukee Brewers 15-2 on Wednesday.

Andres Torres, Aubrey Huff and Posey all homered in a four-run first inning for light-hitting San Francisco, which banged out 18 hits and set season highs in runs and home runs.

Posey's grand slam highlighted a seven-run fourth inning, which began the onslaught. He went 4-for-4 with a career-high six RBIs and also scored three times.

The rare offensive outburst made life easy for Lincecum (9-4), who had been 0-2 with a 7.99 ERA in his last two starts. He ended the slide emphatically by allowing one run and four hits in seven innings with 10 strikeouts and two walks.

A solo homer by Rickie Weeks in the third inning was Lincecum’s only mistake.

His counterpart Chris Narveson was rocked for 10 runs – nine earned – and nine hits in 3 1/3 innings.