PHOENIX -- Gorkys Hernandez didn't know he was going to play Tuesday night until he arrived at Chase Field and saw his name on the lineup card.

He sure was ready.

Hernandez, subbing for the injured Denard Span, drove in a career-high four runs as the San Francisco Giants exploded for eight runs and 15 hits en route to an 8-4 win over the Arizona Diamondbacks.

"You have to be ready all the time," Hernandez said. "You never know what's going to happen. Especially if you are on the bench, you have to be ready just in case.

"I'm ready. You never know."

Hernandez hit a two-run single in the second inning and added a two-run double during a five-run fifth.

"What a day he had for us," Giants manager Bruce Bochy said. "He just did a terrific job. He gives you great defense. And he got a couple of big hits. That's always nice."

Johnny Cueto (1-0) allowed four runs and six hits in five innings for the Giants.

Cueto was just as effective at the plate, going 1-for-3 while driving in a run. He had a key hit in the second inning to help get the Giants out to a 2-0 lead.

After Eduardo Nunez singled and Joe Panik walked, the Diamondbacks played for a bunt by Cueto. But Cueto crossed them up by hitting a chopper over first baseman Paul Goldschmidt for a single to load the bases, and Hernandez followed with a two-run bloop single.

"I saw the first baseman was very close to me," Cueto said through an interpreter. "I just told myself, I'm just going to swing away."

Right fielder David Peralta saved Arizona more damage by making a diving catch in right-center on a line drive by Hunter Pence to end the inning.

Besides Hernandez's big night, Brandon Crawford had a solo homer and a double while Pence collected three hits for the Giants.

Jake Lamb hit a two-run homer and Paul Goldschmidt hit a solo shot for Arizona.

"A little bit of a frustrating day for us," Arizona manager Torey Lovullo said. "I don't think we played our best game. We didn't execute at times in several different areas."

Arizona's Patrick Corbin (0-1) gave up three runs, two earned, on seven hits in four innings. He walked two and struck out one.

"Not the best results there," Corbin said. "They made me work from the get-go."

In the third, the Giants scored an unearned run when Buster Posey reached on an error by second baseman Brandon Drury. Crawford then doubled off the left-center-field wall.

Posey was caught in a rundown between third and home on a ground ball by Nunez, but Chris Marrero's sacrifice fly scored Crawford.

Arizona drew to within 3-2 in the fourth on Goldschmidt's solo homer and Owings' RBI single.

San Francisco erupted for five runs in the fifth.

Crawford hit a solo homer off Randall Delgado. Nunez singled and scored when shortstop Owings booted a potential double-play ball to make it 5-2.

Hernandez then doubled home two more runs to make it 7-2 and scored on Brandon Belt's double.

"That was an inning where several things didn't go in our favor," Lovullo said. "We didn't pay the type of baseball we normally play."

Lamb hit a two-run homer into the pool in right-center in the fifth to draw Arizona to within 8-4.

NOTES: Giants CF Denard Span sat out Tuesday's game because of a tight hip, manager Bruce Bochy said. He was replaced by Gorkys Hernandez, who made his first Opening Day roster. ... Earlier Tuesday, the Diamondbacks dedicated Paul Goldschmidt Field, the 39th in their youth-field program, in Goodyear. ... The Diamondbacks start the season with 14 straight games (and 17 of 20) against 2016 postseason teams (Giants, Indians and Dodgers). Arizona's come-from-behind win Sunday marked the first time since July 7, 1969, that a team won despite the opposing pitcher hitting two homers. Back then, the Royals' Jim Rooker had a pair of homers in a loss to the Twins. On Sunday, LHP Madison Bumgarner homered twice for the Giants.