DENVER -- Backed by an offense that is heating up, rookie right-hander Antonio Senzatela gave the Colorado Rockies another superb start Saturday night as they pounded the floundering San Francisco Giants 12-3.

The Rockies tallied season-highs in runs and hits (14), getting home runs from Mark Reynolds, who had three hits and four RBIs, Trevor Story and Charlie Blackmon. They scored three runs in the first and fourth innings before a six-run eighth.

The Rockies entered this series batting .224 but scored six runs Friday, albeit in one inning against Johnny Cueto on two homers, in a 6-5 win, and they roughed up starter Matt Moore (1-3) on Saturday.

Moore gave up nine hits, six for extra bases, and six runs in four innings as the Rockies, who had scored four or fewer runs in 12 of their first 17 games, finally erupted.

"That's more like it," Rockies manager Bud Black said. "We had some homers. We had some timely hitting there in the eighth. We had some good swings, good at-bats, we took walks."

Senzatela (3-0) held the Giants to one run -- a Joe Panik solo homer in the sixth -- and four hits in seven innings with no walks and three strikeouts. Senzatela got 10 outs on ground balls in the efficient 90-pitch outing that lowered his ERA to 2.08 in four starts.

Catcher Dustin Garneau said Senzatela wanted to get a feel for his slider at the outset of the game and got outs with that pitch and his changeup -- he threw four of them, three of them effective, Garneau said -- to complement his dependable fastball.

"He didn't throw very many sliders for strikes," Garneau said, "but they were competitive, at least, where they were in and out of the zone and looked like strikes."

The win was the fifth in six games for the Rockies, who are 5-1 this season against the Giants. At 12-6, the Rockies have the second-best record in franchise history after 18 games. They were 13-5 twice and 12-6 three previous times.

Five losses in six games have dropped the Giants to 6-12, the worst in the National League and their worst start since they were 6-12 in 2007. Panik's homer on a hanging 1-2 slider was just the fourth in the past 11 games for the Giants, whose 12 home runs entering the game ranked ahead of just one major league team.

Giants center fielder Denard Span suffered a mild right shoulder sprain when he banged into the wall catching Blackmon's drive to end the second and left the game. He had an X-ray exam after the game and will be unavailable Sunday.

In his last start, also against the Rockies, Moore was on the mound when left fielder Jarret Parker broke his right collarbone when he hit the wall making an inning-ending catch.

"I've been out there the last two times guys are chasing balls down into the wall," Moore said. "You got to feel a little bit responsible for what's going on out there. Hats off to them for just playing hard, going and getting it, not thinking twice about it. So we're hanging tough. There's nobody in here with their head down. We got a lot of season to play."

After Senzatela departed, the Giants scored twice in the eighth on Brandon Belt's double followed by Panik's single to make it 6-3.

Buster Posey followed Panik with a first-pitch single off Carlos Estevez. His wild pitch moved both runners into scoring position for Brandon Crawford, but Estevez struck him out on a 96 mph fastball.

Aided by second baseman Panik's error, the Rockies retaliated in the eighth with six runs, five unearned. They scored on singles by Alexi Amarista (his first RBI and second hit of the season) and pinch hitter Gerardo Parra, Charlie Blackmon's sacrifice fly, Carlos Gonzalez's bases-loaded walk and a two-run single by Reynolds.

After pouncing on Moore for three runs in the first, the Rockies increased their lead to 6-0 in the fourth.

Story led off the inning with his fourth homer of the season. Stephen Cardullo walked and scored on a double into the left-field corner by Garneau, who had one hit in his past 26 at-bats. With two outs, Blackmon cleared the center-field fence for his fifth homer.

Blackmon led off the Rockies' first with a triple, rifling a ball into the right-field corner. He scored on Nolan Arenado's single, and Reynolds swatted his fifth homer, driving Moore's first-pitch 92 mph fastball into the left-field stands.

NOTES: Giants RF Hunter Pence did not start after bruising his left knee Friday night, but he pinch hit and walked in the eighth. ... Giants SS Brandon Crawford will go on the three-day bereavement list next week to attend the funeral Thursday of his sister-in-law Jennifer Pippin, who died of an asthma attack April 12. ... Rockies OF David Dahl (stress reaction sixth rib), who missed most of spring training, took 30 dry swings two days after his latest CT scan showed enough bone formation. ... Rockies RHP Chad Qualls (right forearm tightness) resumed his rehab assignment at Triple-A Albuquerque. ... Rockies 1B Ian Desmond (fractured left hand) should be taking batting practice by early next week and has another X-ray scheduled Wednesday.