Giants 9, Diamondbacks 6: Brandon Belt hit a three-run homer off David Hernandez in the eighth inning and visiting San Francisco completed a three-game sweep of Arizona.

Hunter Pence and Angel Pagan also homered for the Giants, who trailed 6-4 with two on and two outs in the eighth before Belt crushed an 0-2 pitch from Hernandez (1-2) into the right-field bleachers. San Francisco added two runs in the ninth on Pablo Sandoval’s RBI double and Buster Posey’s sacrifice fly.

George Kontos (2-1) tossed 1 2/3 scoreless innings for the win and Sergio Romo worked around a one-out single in the ninth for his 11th save and third of the series. San Francisco recorded its ninth come-from-behind victory while collecting eight extra-base hits.

Cliff Pennington put Arizona ahead 3-1 in the second with a three-run homer off Tim Lincecum, who gave up five runs over five innings and tied his career high with 10 hits allowed. The Giants answered with two runs in the fifth off Brandon McCarthy, who allowed four runs and eight hits over six innings.

Pence blasted the longest home run of his career in the sixth, a 460-foot solo shot that cut the deficit to 5-4. Pennington doubled in a run in the sixth to increase Arizona’s lead and matched his career high with four RBIs.

GAME NOTEBOOK: Belt is 7-for-17 with three homers and nine RBIs in six games against Arizona this season. … Lincecum did not walk a batter for the first time in his last 60 starts. … The Giants have won seven of their last eight games at Chase Field.