PHOENIX -- Even with three regulars on the disabled list and another two given the night off, San Francisco continued to roll Friday against an Arizona Diamondbacks team that cannot shake its troubles at home.

Nos. 5-8 hitters Jarrett Parker, Conor Gillaspie, Grant Green and Trevor Brown had eight hits and drove in all six runs in San Francisco's 6-4 victory at Chase Field, when Johnny Cueto battled through stomach issues to earn his 12th win.

The Giants will send right-hander Jeff Samardzija (8-5) against left-hander Patrick Corbin (4-6) on Saturday as they attempt to win their sixth straight game at Chase Field this season. The D-backs are a league-worst 13-29 at home, and the Giants are a league-best 27-15 on the road.

San Francisco catcher Buster Posey and Denard Span, given Friday off, could be back in the lineup Saturday, manager Bruce Bochy said. But for a night, they were not missed when the reserves came through.

Among the Giants' key contributors Friday, only backup catcher Brown was on the Opening Day roster. The others have stepped in for injured starters Hunter Pence, Matt Duffy and Joe Panik, all of whom are on the disabled list.

"It's one thing for them to contribute," Bochy said of the reserves. "The big way they did tonight, that was key for us. Some guys being down. When that happens, you need somebody to pick it up, and these guys did."

Gillaspie, playing third base while Duffy is in a walking boot recovering from a left Achilles strain, was a homer short of the cycle Friday. A left-hander hitter, he tripled into the right field corner in the second inning, doubled into the left field corner in the fourth and grounded a hit-and-run single through the hole between first and second in the sixth inning. The Giants scored five runs in those three innings, taking a 5-4 lead on Brown's two-out, two-run opposite field double in the sixth.

Gillaspie, who opened the season at Triple-A Sacramento but was quickly promoted, is hitting .459 with nine runs and 11 RBIs in his last 37 at-bats, raising his average to .288.

"It's a crazy game sometimes," Gillaspie said. "But the more you get off yourself, so to speak, and push your own well-being aside and try to be a part of a great organization like this, and the fact that this is a winning ballclub and that is the No. 1 priority, it makes it easier when you are not doing well to look up and say, 'I am on one of the best teams in baseball.' It's very gratifying to know that you are a part of that."

The Giants (51-31) has won 15 of 20 and it tied with the Chicago Cubs for the most victories in the NL.

Jake Lamb, Arizona's third baseman, is on a streak as hot as Gillaspie. Lamb has homered in the last three games, one game short of the franchise record for homers in consecutive games, and he has a team-high 17 this season. Reggie Sanders, Troy Glaus (twice), Mark Reynolds and Mark Trumbo also homered in four straight as Diamondbacks.

Paul Goldschmidt, another Arizona All-Star candidate, doubled in a run Friday and is hitting .376 with eight doubles and 21 RBIs in his last 23 games.

Samardzija enters the game with a 1-1 record in 10 career games (five starts) against Arizona. He beat the Diamondbacks on May 13 at Chase Field, allowing one run in eight innings during San Francisco's 3-1 win.

Corbin got a no-decision against the Giants the next day, giving up three runs in 6 1/3 innings in a game Arizona lost 5-3. In 12 career starts against San Francisco, he is 4-4 with a 3.48 ERA.