Ian Kennedy pitched six solid innings en route to his National League-leading 21st win and added a two-run double, and Gerardo Parra had four RBIs as the NL West champion Arizona Diamondbacks posted a 15-2 victory over the visiting San Francisco Giants on Saturday.

The loss eliminated the defending world champion Giants from playoff contention, as they trail Atlanta by five games in the wild-card race with four to play.

Kennedy (21-4) allowed two runs and five hits in his final start of the regular season to finish 10-0 against division opponents. The 26-year-old went 11-2 at home and won 13 of his final 14 decisions overall.

Kennedy helped his own cause at the plate by capping Arizona's six-run first inning. Ryan Roberts and Parra hit back-to-back two-run singles earlier in the frame against rookie Eric Surkamp (2-1), who yielded six runs on three hits and four walks while retiring only two batters in his fifth career start.

Roberts and Parra drove in a run apiece during a five-run rally in the sixth by the Diamondbacks, who remained one game behind NL Central champion Milwaukee for home-field advantage in the Division Series.

Pablo Sandoval had two hits and two RBIs for the Giants, who have lost four of five.