PHOENIX -- The Arizona Diamondbacks got their first real look Wednesday night at Taijuan Walker, their new, young power arm.

For the most part, they liked what they saw.

Walker wobbled at first but ended up keeping the Diamondbacks above water, allowing the Arizona offense to wear down the San Francisco Giants for an 8-6 victory at Chase Field.

Walker (1-0) pitched six innings, allowing four runs and seven hits. He struck out seven and walked one.

The 24-year-old right-hander and the D-backs fell behind 4-1 midway through the fifth inning, which Walker attributed to the nerves involved in making his first start since being acquired in the offseason from the Seattle Mariners.

"Started off a little rough," he said. "I was kind of amped up, but the last three innings were really good."

Said Arizona manager Torey Lovullo: "When his back was against the wall, he made pitches and kept us in the game. He threw some quality pitches all night. He gave us a chance to win, which is what we want from our starters."

Pinch hitter Jeremy Hazelbaker sent Matt Moore's final pitch of the game into the right field corner to break a 4-4 sixth-inning tie. Hazelbaker's RBI double scored Chris Iannetta, who led off the inning with a single. A.J. Pollock singled home Hazelbaker for a 6-4 Arizona lead.

"The big blow was Jeremy Hazelbaker," Lovullo said. "He put up a quality at-bat with a good approach."

In the seventh, Brandon Drury's run-scoring single and Nick Ahmed's RBI double made it 8-4.

With one out in the eighth, the Giants strung three singles together to chase D-backs reliever J.J. Hoover. Pinch hitter Aaron Hill drew a walk from reliever Andrew Chafin to drive in a run and cut the deficit to 8-5. Chafin turned around and struck out Joe Panik.

Reliever Tom Wilhelmsen threw a wild pitch with his first offering to make it 8-6, then got pinch hitter Chris Marrero to fly out to end the inning.

D-backs closer Fernando Rodney pitched a scoreless ninth to earn the save.

Moore (0-1) pitched 5 1/3 innings, allowing six runs (three earned) and eight hits. He struck out three and walked two.

"I walked three guys today; two of them scored," Moore lamented.

Pollock had three hits for the D-backs, including two doubles.

"We've had a lot of clutch hitting," Pollock said. "We're going to have to keep that going. A big day tomorrow, to take a series from these guys."

Added Walker: "The offense did a great job of picking me up. We have a really good offense, one of the best in the league."

In the second inning, the Giants' Eduardo Nunez singled and stole second. Then second baseman Drury made a great stop on Buster Posey's smash up the middle. Nunez circled third and headed for home, seeming to surprise Drury, who hesitated before throwing to the plate. Nunez barely beat the throw to Iannetta.

In the third, center fielder Pollock misplayed Brandon Belt's routine single into what the official scorer ruled a triple. Pence singled home Belt, and after a single by Posey, Brandon Crawford lifted a sacrifice fly to score Pence.

The Diamondbacks scored in the third when Chris Owings singled home Pollock, who had doubled.

The Giants took a 4-1 lead in the fifth when Belt hit his first home run of the season, a solo shot to right.

The D-backs jumped back into a 4-4 tie in the bottom of the fifth with three unearned runs.

The key play was Belt's error on a ground ball by Jake Lamb near the first base line that allowed Chris Owings (double) and Paul Goldschmidt (walk) to score. Then, Yasmany Tomas doubled home Lamb.

"Belt catches that ball 95 if not 99 percent of the time," Giants manager Bruce Bochy said. "They ended up getting three runs that inning, and that's a momentum-changer there we just couldn't stop."

Belt said, "I got caught in between, and didn't think I was going to have enough time to get in front of it. I tried to backhand it and just couldn't come up with it. It changed the momentum, and it changed the whole ballgame for us."

NOTES: Giants CF Denard Span missed his second consecutive game with a sore hip. Span indicated he doesn't think the problem is serious. "He's doing better today," said manager Bruce Bochy, who cautioned that Thursday is important for Span in "letting us know where he's at." ... 1B Paul Goldschmidt needs one more hit to move into second place on the D-backs' all-time list ahead of Steve Finley (847). Luis Gonzalez is the franchise leader with 1,337. ... The Giants brought in Cody Ross, who played for San Francisco and Arizona, as a part-time coach who will help with the outfielders.