The Giants moved 5 1/2 games in front of the Dodgers in the National League West by winning the opener of a crucial three-game series.
San Francisco forged a 2-2 tie in the sixth on an RBI, infield single from Hunter Pence and then came up with the key hit from a player who is in the midst of a hot streak.
Blanco then stole second and Brandon Crawford drew a walk. The runners moved up on a sacrifice bunt from Emmanuel Burriss, after which Angel Pagan was intentionally walked to load the bases.
That brought up Scutaro, who singled to right on a 1-0 pitch. Scutaro has gone 9-for-17 in his last four games. An infield single in the ninth by Joaquin Arias drove in another San Francisco run.
Santiago Casilla (7-5) picked up the win by working two-thirds of an inning in relief of Tim Lincecum, who allowed only four hits in 6 1/3 and struck out seven. Lincecum, however, walked seven and left the game with one out and two on in the seventh.
Sergio Romo recorded the final four outs for the Giants to collect his 10th save