SAN FRANCISCO -- There undoubtedly will be references to the Cy Young Award race when staff aces Clayton Kershaw of the Los Angeles Dodgers and Madison Bumgarner of the San Francisco Giants duel Thursday afternoon.

Truth be told, though, the Giants' leading candidate for the annual honor might be the guy who pitched Wednesday night.

Right-hander Tim Lincecum lowered his season ERA to 2.08 and extended his streak of scoreless innings at home to 22 with seven innings of three-hit, shutout ball, pitching the Giants to a 4-0 victory over the Dodgers.

"I talk about rhythm a lot," the two-time Cy Young Award winner said. "I've found a good rhythm. I'm trying to ride it out."

San Francisco's fifth consecutive win was its second in two nights over Los Angeles, trimming the Dodgers' lead in the National League West to 2 1/2 games. The Giants beat the Dodgers for the sixth time in eight meetings this season.

Shortstop Brandon Crawford's third hit of the game, a two-out RBI single in the sixth inning, ended a scoreless duel. Catcher Buster Posey belted a two-run homer in the seventh as the Giants won their fifth straight over Los Angeles, the longest streak against their rival since 2003.

"He looks confident right now," Crawford said of Lincecum, behind whom the Giants played error-free ball. "He's locating his fastball better and keeping his pitches down. When he's doing that, he pitches better."

The Dodgers' loss followed news earlier in the day that left-handed starting pitcher Hyun-Jin Ryu will undergo arthroscopic surgery on his left shoulder Thursday in Los Angeles. Ryu is expected to miss the rest of the season.

Lincecum (4-2) outdueled Dodgers left-hander Brett Anderson (2-2) in a game played in a steady drizzle beside the San Francisco Bay.

On a night when he passed Hall of Famer Carl Hubbell for fourth place on the Giants' all-time strikeout list, Lincecum won a fourth consecutive home start for the first time since 2009. He struck out four and walked two while lowering his home ERA this season to 1.13.

"It's a good day for the Giants," said Lincecum, downplaying his personal feat. "It's a good day for me."

Lincecum, who finished the night with 1,680 career strikeouts, has recorded at least one whiff in all 254 of his big-league starts, the longest active streak in majors.

He was matched pitch for pitch by Anderson for five innings before the Giants finally broke through in the sixth after a leadoff double by Posey, his second of three hits.

Crawford's tiebreaking hit -- a liner just in front of diving left fielder Alex Guerrero -- came with two on and two outs.

"Anytime you can drive a run in, especially late in a tie game, it's a pretty good feeling," Crawford said. "I don't know if anything can compare with a walk-off hit, but that one (a late tiebreaker) is right up there."

The Giants broke the game open in the seventh, scoring first on an RBI single by second baseman Joe Panik, which ended Anderson's night.

Posey, who earlier extended his hitting streak to 12 games, then greeted right-handed reliever Yimi Garcia with a two-run shot to center field, his seventh homer of the season.

Anderson was charged with three runs on six hits in 6 1/3 innings. He walked three and struck out seven.

"Brett was really good," Dodgers manager Don Mattingly said. "He seems to be getting stronger. I'm happy with the way he's throwing the ball."

Right-hander Jean Machi and lefties Javier Lopez and Jeremy Affeldt pitched the final two innings for the Giants, who recorded their majors-leading seventh shutout of the season. San Francisco won the series opener Tuesday 2-0 behind right-hander Tim Hudson.

Second baseman Howie Kendrick had two hits, including a double, for the Dodgers, who have scored only two runs in their past 39 innings.

"Every team I've ever coached, every team I've ever managed, every season I've ever played, you go through two or three of these (slumps) a year," Mattingly said. "This is the first."

Lincecum recorded his milestone strikeout in the top of the sixth, fanning Dodgers first baseman Adrian Gonzalez with two outs. It was his fourth strikeout of the game.

NOTES: The top three pitchers on the Giants' all-time strikeout chart are RHP Christy Mathewson (2,504), RHP Juan Marichal (2,281) and RHP Amos Rusie (1,838). ... Giants SS Brandon Crawford collected two or more hits for the fifth time in seven games. ... Asked if he expected LHP Hyun-Jin Ryu to return this season following his scheduled shoulder surgery Thursday, Dodgers manager Don Mattingly admitted, "I didn't get that feeling." ... Thursday's series finale pairs reigning National League Most Valuable Player LHP Clayton Kershaw of the Dodgers and World Series MVP LHP Madison Bumgarner of the Giants for the third time this season. The Giants won the first two head-to-heads, 3-2 in San Francisco and 2-1 in Los Angeles. ... The Giants announced before the game that RHP Jake Peavy (strained back) would be sent to Class A San Jose to pitch one inning in a rehab start Friday.