Kershaw lost another low-scoring duel against last year's World Series and NLCS MVP, giving up a home run and an RBI single to Buster Posey in the Los Angeles Dodgers' 2-1 loss to the archrival San Francisco Giants on Tuesday night.
Kershaw (1-2) allowed seven hits over seven innings before he was lifted for a pinch-hitter. The reigning NL MVP and three-time Cy Young Award winner — coming off his fourth consecutive major league ERA title — had a 1.95 ERA in his four previous starts against Bumgarner.
"I gave up two, he gave up one. He pitched eight innings, I pitched seven. So, yeah. I got outpitched," said Kershaw, who was trying for his 100th regular-season victory. "I have a lot of respect for Madison and what he does, but I don't care who I pitch against."
Bumgarner (2-1) gave up five hits, struck out nine and walked one while throwing 110 pitches. He is 3-1 lifetime against Kershaw, who was his mound opponent six nights earlier in San Francisco when neither got a decision in the Giants' 3-2 win.
"It's going to bring out the best in you, for sure. There's no way around that," Bumgarner said. "You know that anytime you're facing him, it's going to be tough to scratch some runs across. And we were able to score just enough to win, so it was a big win for us."
The Giants took the lead in the first when Angel Pagan lined a two-out double off the fence in left and scored on Posey's single.
Posey, who came in with a .177 career average against Kershaw, ended an overall home run drought of 49 at-bats by driving his first pitch of the fourth inning to left-center for his third of the season, helping end the Dodgers' eight-game home winning streak.
"You figure it's going to be a tight game, which it was," Giants manager Bruce Bochy said. "I think when pitchers go up against a certain pitcher, they know they'd better pitch well because they don't expect a lot of runs. That's how Madison thinks, and he had good focus. I think he understands that he's got to be on top of his game when he's going against Kershaw."
The Dodgers, playing without injured corner outfielders Carl Crawford and Yasiel Puig, had a starting outfield of rookie Alex Guerrero in left, rookie Kike Hernandez in center, and Scott Van Slyke in right.
The trio was a combined 3 for 11. Guerrero took over for Crawford, who was placed on the 15-day disabled list before the game because of a torn right oblique muscle.
"It certainly was different," Bumgarner said of the Dodgers' patchwork lineup, which included Justin Turner at first base. "I thought: 'When's the next time I'm going to face a lefty?' But I don't mind either way. You've still got to make pitches to whoever you're facing."
Regular center fielder Joc Pederson and first baseman Adrian Gonzalez were rested against the left-hander. So was left-swinging outfielder Andre Ethier, who has been playing regularly in place of Puig. Gonzalez is 4 for 35 against Bumgarner and Ethier is 3 for 24.
"It's a good feeling," Bumgarner said. "But at the same time, Gonzalez is a great hitter and I've seen him do a lot of special things. So I'm not going to take anything for granted, that's for sure."
Santiago Casilla pitched a perfect ninth for his sixth save in seven chances.
Giants: RHP Matt Cain, who has been on the DL since the start of the season because of a strained right flexor tendon, played catch in the outfield.
Dodgers: Closer Kenley Jansen threw 20 pitches in a simulated game, the last one clocked at 96 mph. "I would say I'm on schedule," said Jansen, who had surgery in February to have a benign growth removed from his left foot. "There's no 'ahead of schedule,' because the injury I was dealing with is the kind of thing you don't want to play around with. So I've just got to wait for the 12 weeks to be over with, and then I'll probably get activated." ... LHP Hyun-Jin Ryu (shoulder impingement) threw 25 pitches during a bullpen session and will have another one on Friday.
Giants: RHP Ryan Vogelsong (0-1) makes his third start of the season and second straight against the Dodgers, after giving up two runs over six innings in a no-decision last Thursday in San Francisco. The runs came on homers by Guerrero and Gonzalez.
Dodgers: RHP Zack Greinke (3-0) brings a 1.35 ERA into his fifth start, after pitching seven innings of four-hit ball last Friday in a 3-0 win at San Diego. The 2009 AL Cy Young winner is 19-4 with a 2.37 ERA in 31 starts at Dodger Stadium since signing a 6-year, $147 million contract with the club in December 2012.