PHOENIX (AP) Chris Heston plunked the first batter he faced and compounded it by throwing the ball into right field while trying to pick him off. The two-base error led to a run, not exactly the start a pitcher going for his first big league win wanted.
Heston didn't seem to mind. He shook off the miscues and a wild pitch that led to another run, earning that coveted first win.
Heston pitched six effective innings in a combined five-hitter, Casey McGehee hit a two-run homer and the San Francisco Giants beat the Arizona Diamondbacks 5-2 Wednesday night.
''The first inning started to unravel a little bit, kind of a little shaky there,'' Heston said. ''But I was able settle down and get back into it.''
Heston (1-0) got off to an inauspicious start, but stayed steady in his second big league start, winning for the first time after going winless in three appearances last season.
Jean Machi and Sergio Romo followed with a pair of scoreless innings each and Santiago Casilla worked around a single in the ninth inning for his second save.
The Giants, who entered the season with plenty of offensive questions, gave him plenty of support, banging out 14 hits against the Diamondbacks to finish with 37 in the three-game series.
Nori Aoki had three hits, including a run-scoring double off Jeremy Hellickson (0-1) in the right-hander's Arizona debut.
''Good at-bats, they were using the whole field,'' Giants manager Bruce Bochy said. ''Good to see the guys get some confidence going.''
Arizona knocked around Ryan Vogelsong in a 7-6 win Tuesday night, but went down quietly against Heston and the Giants' relievers.
The Diamondbacks went 0 for 8 with runners in scoring position, needing miscues by the Giants to score its two runs in losing their ninth straight series to San Francisco at Chase Field.
''We were in every game,'' Arizona manager Chip Hale said. ''We lost the first one by one and this one by three. If we give up a lot of hits, we give up a lot of hits, as long as we don't give up a lot of runs.''
The Giants slid Heston into the rotation after right-hander Matt Cain went on the disabled list with a strained flexor tendon in his throwing arm.
The Diamondbacks scored a run off Heston without a hit in the first inning, when leadoff hitter A.J. Pollock was hit by a pitch, reached third on a throwing error by Heston on a pickoff move and scored on Chris Owings' groundout.
Arizona tacked on another run in the sixth inning after Goldschmidt doubled, advanced to third on a wild pitch and scored on catcher Hector Sanchez's passed ball.
Heston allowed two unearned runs on three hits and struck out five.
''What a job he did; good for Chris,'' Bochy said. ''He was a little amped up that first inning, threw it away, but settled down and really did a nice job.''
Hellickson arrived in Arizona in an offseason trade with Tampa Bay, hoping to bounce back from a difficult 2014 season in which he started on the disabled list and went 1-5 with a 4.52 ERA.
Hellickson, who turned 28 on Wednesday, was in trouble from the start against the Giants, though escaped a one-out, bases-loaded jam in the first inning.
San Francisco scored two runs off him in the second inning on consecutive run-scoring doubles by Aoki and Matt Duffy. Brandon Crawford added a run-scoring single to make it 3-1.
''I felt really good,'' said Hellickson, who allowed three runs on nine hits. ''I just had no command of anything.''
Giants: RHP Tim Hudson will make the first start in the final season of his 17-year career at San Diego on Thursday. The 39-year-old had surgery to remove bone spurs from his right ankle during the offseason, but had a decent spring, going 1-1 with a 3.32 ERA.
Diamondbacks: Arizona has a day off before RHP Chase Anderson makes his 2015 debut against the Los Angeles Dodgers on Friday.
Giants: 1B Brandon Belt was held out of the lineup after straining his groin Tuesday night, but is not expected to go on the DL. He was able to take a few swings in a batting cage on Wednesday and (manager Bruce) Bochy said he should be available this week. ... RHP Jake Peavy's stiff lower back loosened overnight and is still on schedule to start Sunday against San Diego.
Diamondbacks: LHP Patrick Corbin, who underwent Tommy John last season, is expected to go on rehab assignment in May and possibly return by early June.