Jonathan Sanchez pitched five strong innings and ignited the game-winning rally in the third as the San Francisco Giants clinched the National League West on Sunday with a 3-0 victory over the San Diego Padres.

Rookie Buster Posey homered and Aubrey Huff recorded two hits and an RBI for San Francisco, which won its first division title since 2003.

Chris Denorfia collected three of the four hits by the Padres, who finished two games back in the West and one behind Atlanta in the wild-card race.

Sanchez hit his first career triple with one out in the third and scored two batters later on a single up the middle by Freddy Sanchez. Aubrey Huff followed with an RBI double to deep left-center field, giving the Giants a 2-0 lead.

Posey added insurance in the eighth with a leadoff home run, his 18th of the season.

Sanchez (13-9) limited San Diego to three hits - all singles - but walked five. The left-hander, who had gone 0-3 in five starts against the Padres this year, struck out five en route to his fifth win in six decisions.

Brian Wilson worked a perfect ninth for his major league-best 48th save.

Mat Latos (14-10) surrendered two runs and eight hits in six innings. The 22-year old, who struck out four without a walk, lost each of his last five starts.