"I felt better as the game went on," Bumgarner said. "I was making pitches and making adjustments. I was having a hard time getting the outside corner early on, but I got to where I could hit that spot the last two or three innings."
San Francisco's 12th victory in 15 games was overshadowed, however, by the broken left thumb first baseman Brandon Belt sustained when he was hit by Paul Maholm's first pitch of the second inning. Belt will be sidelined for at least six weeks, according to manager Bruce Bochy.
The Giants were leading 3-0 when Puig homered to center in the sixth, after taking a called third strike his previous time up and stranding Justin Turner at third base. As soon as Puig made contact, he flipped the bat away, walked a few feet toward first base and began a slow trot around the bases.
"Honestly, I think Puig overreacted a little bit. I don't know," Dodgers teammate Scott Van Slyke said. "He felt like he had an unfair pitch thrown to him the previous time up, and then he acted like he got him back. But Puig's an emotional guy. Some people just have that fire in them when they play, and it comes out sometimes. I wouldn't necessarily say that it's wrong or right. It's just that there's lots of different personalities in the world, and you've just got to learn to deal with them."
Bumgarner walked toward the third-base line and had a few choice words for Puig as he approached home plate. But the hostilities ended there with some quick action by plate umpire Will Little, who intercepted Bumgarner.
"I was just congratulating him," Bumgarner said, tongue in cheek. "That was a really good swing. That was pretty impressive. I don't know why everybody got so mad. It escalated quickly for no reason.
"I think he said, `Thank you.' I'm not sure if he did. I don't speak Spanish very well. But it's always a passionate series when you play the Dodgers, and it's fun. No matter what the records are, either team could be 30 games out and it's still going to be a big series just because it's the Giants and Dodgers."
Hanley Ramirez was the next batter and took a 1-1 pitch for a strike that had manager Don Mattingly chirping from the dugout. Little ejected Mattingly, who came running out to argue.
Belt, who leads the Giants with nine homers, ran the bases until the second inning ended but was replaced on defense by Joaquin Arias.
"When I looked at it, I said: `It's not good.' He couldn't move it, and it was just locked," Bochy said. "I had a bad feeling it was broken and that he was going to have to come out of the game.
"It's the old bittersweet thing," he added. "It was a great game and a great performance by Bumgarner, so you appreciate that. But at the same time, we lost our first baseman. And that's a blow for us because of the job he does at first base and the fact that he hits in the heart of our order."
Bumgarner (4-3) allowed a run and four hits with eight strikeouts en route to his second straight victory after three consecutive losses -- two of them by 2-1 scores against the Dodgers and Colorado. He is 5-1 with a 1.45 ERA in his past six starts at Dodger Stadium, and hasn't allowed more than two earned runs in any of them.
"He's good at missing just high, or just outside, or just inside," Van Slyke said. "He's really tall and he throws hard. He has an idea of what he wants to do and his ball moves. And he's a competitor, so he's going to be tough for a lot of years."
Sergio Romo pitched a perfect ninth for his 12th save in as many attempts.
Maholm (1-3) gave up three runs, three hits and four walks in 5⅔ innings. The left-hander is 0-4 with a 6.66 ERA in his past five starts against the Giants.
Maholm got out of a first-inning jam by retiring cleanup hitter Mike Morse on a double-play grounder and matched zeros with Bumgarner until the fifth. Brandon Hicks walked with one out and Crawford drove the next pitch into the right-field pavilion for his fourth homer of the season and first in 117 career at-bats against the Dodgers to that point.
Dodgers reliever Brandon League escaped a bases-loaded, none-out jam in the seventh when he fielded Hunter Pence's comebacker to start a 1-2-3 double play and then retired Buster Posey on a fly to right.
Mattingly's ejection was his 13th as a manager and first this season. ... Puig extended his hitting streak to nine games, matching his longest as a rookie last season. ... Turner started at third base because of Juan Uribe's sore right hamstring. ... It was the 12th time in the Dodgers' past 15 meetings with San Francisco that they have scored fewer than four runs. ... Romo's scoreless inning reduced the ERA of the Giants' bullpen to a major league-best 1.75. ... Maholm, who has induced a major league-high 192 double-play grounders since the start of the 2006 season, hasn't had more than three strikeouts in any of his six starts this season.