MLB: Arizona 3, San Francisco 1

PHOENIX, Sept. 16 (UPI) -- Arizona bested San Francisco Monday 3-1, with Adam Dunn hitting the go-ahead, two-run home run in the eighth inning.

Diamondback starter Doug Davis threw seven innings, giving up one unearned run on eight hits without walking a batter. Tony Pena (2-2) was credited with the win after a perfect eighth and Chad Qualls took the mound in the ninth to earn his fourth save of the season.

Justin Upton hit a solo homer to rack up the other run for Arizona, which snapped a two-game skid to keep from falling further back of Los Angeles in the division..

The Los Angele Dodgers have won 13 of 15 to pull 4 1/2 games ahead of the Diamonds to lead the division, while Arizona has lost eight of its last 10 games.

Brad Hennessey (1-2) went the distance for San Francisco, allowing two home runs among eight hits for the loss.