SAN FRANCISCO -- Second baseman Joe Panik's sacrifice fly to center field scored pinch runner Gregor Blanco in the bottom of the ninth inning Wednesday night, allowing the San Francisco Giants to edge the Los Angeles Dodgers 3-2.

The game began as a historic duel between left-handers Clayton Kershaw of the Dodgers and Madison Bumgarner of the Giants in the first ever pitching matchup of a reigning National League Most Valuable Player and a reigning World Series MVP. Neither disappointed in the fourth head-to-head of their careers.

In the end, though, the game turned into a battle of the bullpens, and the Giants' prevailed.

San Francisco plated the game-winner against the Dodgers' fourth reliever, left-hander J.P. Howell, who inherited a two-on, one-out situation from righty Chris Hatcher (0-2).

Catcher Buster Posey put the eventual winning run on the bases in the ninth with a one-out single against Hatcher.

After right fielder Justin Maxwell was hit by a pitch, Howell relieved Hatcher, and Blanco pinch-ran for Posey.

First baseman Brandon Belt's single loaded the bases, and Panik hit the next pitch to medium-deep center field to end it and give the Giants just their second two-game winning streak of the season.

Right-hander Santiago Casilla (1-0), the fourth Giants pitcher, got the win after pitching a scoreless ninth inning.

Right-handers George Kontos, Sergio Romo and Casilla held the Dodgers scoreless on one hit over 2 2/3 innings in relief of Bumgarner. The Giants' bullpen has allowed just one run in its past 11 innings.

Neither starting pitcher factored in the decision.

Bumgarner took a 2-0 lead into the bottom of the sixth inning and appeared to have gotten the better of Kershaw when Dodgers manager Don Mattingly elected to pinch-hit for his ace following a one-out single by catcher A.J. Ellis.

Three pitches later, pinch hitter Alex Guerrero bombed a home run into the left field bleachers, tying the score and ending Bumgarner's night.

The pinch-hit homer was Guerrero's second of the season and third overall in just eight games.

Bumgarner failed to earn his second win of the season despite limiting the Dodgers to two or fewer runs for the fifth time in their last six encounters. He gave up two runs, six hits and two walks in his 6 2/3 innings, striking out six.

Kershaw was even better, although also the victim of a two-run inning when the Giants put together a walk and two hits in the third inning. He permitted just one other hit and no more walks in his six innings. He struck out nine.

Kershaw was attempting to become the second-youngest active pitcher to record 100 wins at age 27 years and 34 days. Other than Seattle Mariners right-hander Felix Hernandez, who recorded his 100th win at age 27 years and 14 days, the only other active pitcher to reach the century mark before turning 28 was New York Yankees lefty CC Sabathia (27 years, 69 days).

Other than the two that scored, the Giants never got a baserunner as far as second against Kershaw, whose nine strikeouts gave him 35 in 24 1/3 innings this season.

The Dodgers, meanwhile, put at least one runner on base in all but the fourth inning against Bumgarner. They stranded a runner at second base in both the fifth and sixth innings before finally breaking through in the seventh.

NOTES: RHP Mike Bolsinger will be promoted from Triple-A Oklahoma City to start for the Dodgers in Thursday's series finale, and RHP Ryan Vogelsong will pitch for the Giants. ... The Dodgers called up CF Chris Heisey from Oklahoma City and inserted him into the starting lineup. LHP Adam Liberatore, who was unscored upon in 4 1/3 innings, was sent to Triple-A. ... The Dodgers made a trade earlier in the day, acquiring LHP Xavier Cedeno from the Washington Nationals for cash. Cedeno pitched in five games for the National