DENVER -- With the new MLB rule forcing pitchers to face a minimum of three batters under most circumstances, the Rockies’ lineup can leave opposing teams and managers with maximum stress. Giants skipper Gabe Kapler had to deal with plenty of that on Thursday afternoon.

After Giants left-handed starter Tyler Anderson held his former club scoreless on two hits over five innings -- departing after his unstretched arm had thrown 66 pitches -- Trevor Story, Daniel Murphy and Charlie Blackmon swatted home runs off overmatched relievers in the Rockies’ 6-4 victory at Coors Field.

• Box score

“Sometimes it works to your advantage as an offensive team -- it’s showing more of that to me as we go on,” Rockies manager Bud Black said. “It’s just another reason when you’re talking about your bullpen, they’d better have the stuff and they’d better be equipped to handle left- and right-handed hitters.”

With the come-from-behind victory, the Rockies have opened a season with four series wins for the first time in franchise history. Colorado won three of four in this series and five of seven on the homestand. At 9-3, the Rockies have tied their second-best 12-game start in club history (1997), trailing only the 2011 season, which they started 10-2.

The latest victory occurred because the Rockies taxed the Giants’ bullpen, a theme of the series. The Giants’ starters posted a 2.66 ERA and struck out 18 against five walks in 20 1/3 innings. But when those starters hit the showers, the Rockies’ bats cleaned up, as they have against relievers all season. Through 12 games, Colorado has hit .294/.362/.508 (.870 OPS) with 11 home runs.

“That’s a huge part of this year -- it’s already a crazy year,” said Story, who has five homers (with just five strikeouts) this season -- and has 21 home runs in 70 career games against the Giants. “Anything we can do to get to the ‘pen and have someone go through at least three hitters in our lineup, whether it’s lefty or righty, we feel good about that.”

Black acknowledged possible fatigue during a stretch with a packed schedule by making Story the designated hitter and resting Murphy for much of the afternoon. The move did not slow the Rockies, who showed that their balance and depth can be effective no matter the starting lineup.

Story, the second batter faced by lefty Wandy Peralta in the sixth, homered for a 1-0 lead. After Colorado lefty Kyle Freeland saw a resourceful start (eight hits, but 11 ground-ball outs and three double plays) negated by Mauricio Dubón’s homer with two outs in the top of the seventh, the Rockies took advantage of one of this season’s new rules to flip the game.

Giants reliever Rico Garcia, who debuted with the Rockies last season, gave up right-on-right doubles to Garrett Hampson and Chris Owings. Black then replaced righty-swinging catcher Drew Butera with Murphy, who pulled his second home run of the season and fifth career pinch-hit homer over the wall in right.

While rounding the bases on his homer, Murphy appeared to stare toward center field in the direction of Dubón, whose exuberant celebration after his own homer a half-inning earlier likely didn't sit well with Murphy.

“I didn't notice it when it happened,” Dubón said. “When I came in, they told me about it. I thought it was cool. Honestly, I thought it was pretty awesome.

"What Daniel did, it is what it is. It's something that's been going on around the league forever, so he's probably trying to get me grounded. I respect him a lot, and like I said, I enjoy what he did, too.”

Murphy's drive was also the first pinch-hit home run in the Majors this season.

“The whole inning starts long before I get up there,” Murphy said. “Hampson had a great at-bat, and [Owings] as well. I felt like even if I missed one, if I missed low and to the pull side, I could get ‘C.O.’ to third base with nobody out.

“It took some of the pressure off.”

That brought the lineup to the top, so Kapler hoped lefty Caleb Baragar could handle left-hitting David Dahl, right-swinging Story and left-hitting Blackmon. Well, Baragar got the righty. Dahl beat out an infield single, then Blackmon -- who earlier extended his hit streak to 10 games, and is at .396 after a 2-for-3 day -- swatted his second homer of the season.

The Rockies’ usual lineup tilts extremely left. When Matt Kemp is not the designated hitter, Story and Nolan Arenado are the only righty hitters. On those days, however, going left-right-left-right (Dahl-Story-Blackmon-Arenado) at the top is a matchup challenge for starters and relievers. Kemp is a weapon off the bench, as is the infield-outfield versatility of Owings, who started for Story at short, and Hampson, who played second.

Thursday, Black let the game situation determine when to play his Murphy card. With one on and a two-run deficit, he sent Raimel Tapia to the on-deck circle. But when Owings doubled in a run, Murphy went to the plate and swatted the Rockies to a 4-3 lead.

“With the expanded rosters, all the guys who start on the bench -- myself, Tapia and [Sam Hilliard] -- we’re always staying prepared,” Murphy said. “I’d gone and hit in the cage, and you’re always trying to play out situations in your head of what may happen.”

Murphy could not recall facing Garcia last year in Rockies Spring Training. But he had enough knowledge.

“I watched some film on him about three or four days ago and had an idea of what the ball was going to do, and was able to work in a positive count -- 2-0 -- and get my swing off,” Murphy said.