The Giants fell despite first baseman Brandon Belt hitting a home run for the fourth consecutive game, a two-run shot that tied the game at 3-3 in the sixth inning.

With his 10th home run of the season, Belt became the first Giant since Randy Winn in 2005 to hit a home run in four straight games.

Neither team scored again until Chris Iannetta and Charlie Blackmon drew consecutive one-out walks off the sixth Giants pitcher, Pierce Johnson (2-2), in the 12th.

Cory Gearrin came on to get Gerardo Parra to fly to left field before walking Nolan Arenado to load the bases and set the stage for Gonzalez's game-winning hit.

Rockies closer Wade Davis worked a hitless bottom of the 12th for his major-league-leading 16th save. He struck out Brandon Crawford looking to open the inning, prompting the ejection of the San Francisco shortstop and Giants manager Bruce Bochy for arguing a low called strike on a full count.

Jake McGee (1-2), who pitched scoreless ball in the 10th and 11th innings, got the win.

Belt's homer came after the Rockies scored three runs in the second inning, on a two-run double by Daniel Castro and on starting pitcher Chad Bettis' two-out RBI single for a 3-0 lead.

Neither starting pitcher got a decision, although both padded their offensive stats.

Bettis was lifted after six innings, having allowed three runs and five hits. He walked two and struck out five.

Bettis' run-scoring single in the three-run second produced his first RBI of the season and the fifth of his career.

San Francisco's Jeff Samardzija worked two outs into the seventh inning. He also gave up three runs on five hits. He walked three and struck out three.

One of the top run-producers at the plate among pitchers with 11 in the last two seasons, Samardzija set up Gorkys Hernandez's sacrifice fly in the third with a single that advanced Austin Jackson from second to third. It was his first hit of the season.

Parra, Arenado and Castro had two hits apiece for the Rockies, who improved to 2-1 on a nine-game trip.

Belt and Jackson had two hits each for the Giants, who have lost two straight following a three-game winning streak.

--Field Level Media