The Giants rallied at home against D-backs' reliever Tony Sipp in the ninth when Brandon Belt hit his first career game-winning hit, a walk off single, to send the D-backs to a 5-4 loss in the series opener.
The D-backs blew a two-run lead in the eighth inning when Giants' catcher Buster Posey hit the game-tying home run off of David Hernandez.
D-backs starter Wade Miley was impressive on the mound against the Giants, allowing two runs on seven hits in 6.2 innings. Unfortunately, the D-backs' bullpen cost Miley the win.
The D-backs' left-hander is 2-0 with a 2.77 ERA and 23 strikeouts in four starts this season.
Miley also hit a fifth inning home run -- his first carer long ball -- off Giants' starter Ryan Vogelsong. His home run was the first hit for a D-backs pitcher this season.
Prior to Monday's game, Miley was 0-for-5 at the plate this year and just 12-for-83 in his career with a .145 average and two doubles.
D-backs' relievers David Hernandez and Tony Sipp combined to allow three runs on four hits in two innings of work. Hernandez suffered his first blown save of the season, while Sipp was handed his first loss.
• The D-backs played in their third straight one-run contest.
• Miley has yet to record a win in three career starts and four appearances against the Giants.
• Cody Ross made his first trip back to San Francisco since signing with the Boston Red Sox before the 2012 season. Ross went 1-for-4 with two RBI against the Giants on Monday night.
The D-backs and Giants will play the second game of their three-game series at 7:15 p.m. MST. Left-hander Patrick Corbin (2-0, 1.42 ERA) will get the start for Arizona. He will be opposed by right-hander Matt Cain (0-2, 7.15 ERA) for San Francisco.