Madison Bumgarner made a strong start toward showing he deserved the five-year contract extension he signed Monday, leading the Giants to a 4-2 win over the Philadelphia Phillies at AT&T Park on Tuesday.

The home team had another shaky first inning, but this time didn’t let two errors — one by Bumgarner and one by shortstop Brandon Crawford — turn into any runs. Bumgarner settled down after that, lasting six innings while scattering seven hits and a walk and allowing two runs.

Melky Cabrera got the scoring started early for the Giants when he snapped an 0-for-12 streak with an RBI triple in the first inning.

Pablo Sandoval extended his hitting streak to 11 games with a double in the fifth, and later scored on a single by Nate Schierholtz, who had three hits in the game. Schierholtz narrowly missed a home run in the third inning, only to see the ball hit just a few feet below the top of the brick wall in right field.

Buster Posey went 3-for-4 for the second consecutive game and stole third before scoring on a groundout by Crawford.

In the first save situation since losing Brian Wilson for the season, Santiago Casilla came in to pitch the ninth, and closed it out with a scoreless inning. Crawford made a diving play on a ball hit by Phillies outfielder Shane Victorino and a strong throw for the final out. Casilla recorded six saves last year while filling in for Wilson at the end of the season.

NOTES: Crawford’s error in Monday’s game was changed to a hit Tuesday. ... Emmanuel Burriss stole second in the eighth inning, bringing the team’s season total to six. All but one have come at AT&T Park.