Kelly Johnson homered twice and fell a single shy of the cycle and the steamrolling, first-place Diamondbacks won their seventh straight, a 15-4 rout of the Marlins on Monday night.
"We're hot, man," Arizona's Miguel Montero said, "really hot."
Johnson, with a double and triple, tied a franchise record with four extra-base hits.
"A big win," he said. "Lots of runs, lots of hits, you can't ask for anything better than that."
Justin Upton tied his career best by going 5 for 5 -- including a two-run homer into the upper deck -- and Montero matched his career high with five RBIs, including a three-run homer, as the Diamondbacks won for the 13th time in 14 games and 15th in their last 17.
"This is a very confident team," Johnson said, "a lot of momentum, a lot of just mojo, a lot of swagger, I mean, all of it, everything you're looking for in a winning team. It's been a lot of fun together. It's group winning."
Arizona's 19 hits were one shy of the franchise record for a nine-inning game and they came in Florida's most one-sided loss of the season.
"We had an aggressive bunch out there today," Arizona manager Kirk Gibson said. "They put themselves in good position, in good counts, and didn't miss balls."
The Diamondbacks, in the opener of a seven-game home stand after a 6-1 road trip, stayed one-half game ahead of San Francisco in the NL West after two seasons deep in the division basement.
Gerardo Parra hit the other of Arizona's five home runs.
Johnson, batting .429 in his last eight games after an awful start to the season, became the second player in the majors this year to have four extra-base hits in a game. He hit solo home runs in the third and sixth, doubled in the fourth and tripled in the seventh.
"I feel confident, I feel good, I feel strong," he said. "I'm not trying to do too much, just hit the ball real hard."
Johnson came up in the eighth with a chance to hit for the cycle and was struck out by closer Leo Nunez, who was getting some work despite his team's 11-run deficit.
The Marlins, coming off what had been their most one-sided loss of the season -- 8-0 to the Dodgers in Los Angeles on Sunday -- have given up 23 runs and 36 hits in their last two games. They have lost three of four.
Florida was without three-time All-Star shortstop Hanley Ramirez, who left Sunday's game at Los Angeles with stiffness in his lower back.
Saunders allowed four runs and seven hits in six innings, striking out seven and walking two. Volstad gave up five runs and eight hits in 3 1/3 innings with two strikeouts and one walk.
"It's all about the pitching," Florida manager Edwin Rodriguez said. "We have been saying that all along. The starting pitcher sets the tone for the game. That happened yesterday with Ricky Nolasco and that happened today. It's all about pitching."
The Diamondbacks scored 10 straight runs after Gaby Sanchez's two-run homer cut the Diamondbacks' lead to 5-4 in the fifth.
"They have a lineup full of left-handed hitters and they know what they are doing at the plate," Rodriguez said. "All those hits, home runs from the lefties, were opposite field. They are playing well. Everything is falling into place for them."
The Diamondbacks broke it open with a five-run sixth. After Johnson's home run, Melvin Mora grounded to shortstop for the second out. Upton and Drew singled, then on a double steal, reliever Ryan Webb threw wild to third allowing a run to score. Young walked, then Montero's opposite-field homer made it 11-4.
Upton's towering home run into the tables in front of the Friday's Front Row Sports Grill came off Mike Dunn in Arizona's four-run seventh.
Arizona's 15-2 stretch ties a franchise mark. ... Ramirez missed Thursday's game at San Francisco because of a bruised right foot after he was hit by a pitch. ... On last June 1, Arizona was 20-33, 11 1/2 games out of first place. ... Florida's Logan Morrison walked and singled and has reached base in all 31 games he's played this season, the longest active streak in the majors.