Rapid Reaction: Giants 3, Red Sox 2

SAN FRANCISCO -- The night began with optimism as top prospect Xander Bogaerts made his major league debut Tuesday.

But it ended in frustration for the Boston Red Sox, with reliever Brayan Villarreal walking in the winning run in the bottom of the ninth as the San Francisco Giants sank the Sox 3-2 at AT&T Park.

Villarreal, who was recalled from the minors Monday, was summoned for his Boston debut with the bases loaded and two outs in a tie game. He promptly ran the count to 3-0 to Marco Scutaro, then painted a fastball on the outside corner that was called a ball, allowing Roger Kieschnick to trot home with the winning run.

Lefty reliever Franklin Morales began the inning for Boston but allowed a single, a walk and then hit Hector Sanchez with a pitch to load the bases.

Bogaerts, one of the major leagues’ marquee prospects, went 0-for-3 and stranded four runners in scoring position.

But he came up with a terrific defensive play to end the fifth. With a runner on third and two outs, Bogaerts charged Marco Scutaro’s slow bouncer and quickly unloaded an off-balance throw to first to get the diving Scutaro on a bang-bang play.

Red Sox starter Jake Peavy did a masterful job dodging trouble throughout his 5 2/3 innings.

He stranded runners in scoring position in the second, fourth and fifth innings as the Red Sox clung to a 2-1 lead.

Peavy was in the middle of another escape job in the bottom of the sixth when manager John Farrell came out to pull him. Peavy did not appear pleased.

Cameras caught him shaking his head and muttering, “Are you kidding me?” as Farrell made his way to the mound. But reliever Craig Breslow wound up getting the third out, coaxing Brandon Crawford into a grounder to second base and stranding Brandon Belt at second. Belt doubled to lead off the inning.

The Giants were 0-for-10 with runners in scoring position through the first eight innings. But they tied it in the eighth off Junichi Tazawa when Buster Posey’s sacrifice fly in foul territory scored Scutaro. Right fielder Shane Victorino could have let the ball drop and denied Scutaro a chance to score, but Victorino took the sure out.

The Red Sox got to Giants starter Ryan Vogelsong quickly in the first.

Jacoby Ellsbury singled to right and stole second. Victorino was hit by a pitch and Dustin Pedroia singled to load the bases. Mike Carp delivered a sacrifice fly, but Boston did no more damage.

Will Middlebrooks reached on an infield single to load the bases again, but Daniel Nava flied to left for the second out, then Bogaerts grounded out in his first big league at-bat.

Victorino made it a 2-0 lead when he led off the third with a homer off Vogelsong, sending a 3-2 pitch over the left-field wall.

The Giants trimmed the lead to 2-1 in the fifth when Joaquin Arias’ triple to the left-field corner scored Kieschnick.