SAN FRANCISCO -- The Giants were officially eliminated from finishing first in the National League West on Monday night, but they suddenly find themselves in quite a heated battle to escape last place.

It's not much of a consolation prize after winning the World Series a year ago, but it's clear the Giants aren't limping to the finish after their second straight walk-off win, a 3-2 victory over the Colorado Rockies at AT&T Park.

After the Giants trailed 2-1 for much of the game, Brandon Belt tied things up with a two-out RBI double in the eighth. Then the first baseman won it with a one-out run-scoring single in the 10th.

To be sure, Belt and his teammates aren't looking or sounding like a team apathetically playing out the string.

"We want to finish as strong as we can, no matter what situation we're in," Belt said. "I believe there's some momentum to be gained that we can carry into next year. I don't see why we can't go on a run, end on a good note and take it into next season."

Before their game was complete, the Giants were ousted from the N.L. West race with the Los Angeles Dodgers' 8-1 victory over Arizona. But the bottom of the division has become a real horse race of also-rans.

The Giants, Rockies and San Diego Padres are now separated by a mere one game in the standings to determine third, fourth and fifth place. The Giants have brought up the rear in the division for the better part of 11/2 months but over their final 18 games can still avoid a first-to-worst development and finish as high as third.

Giants starter Tim Lincecum, who allowed just seven hits, two runs and one walk over eight innings, said no one on the club is cashing in his chips early.

"We come in here with a purpose every game, regardless of the standings," Lincecum said. "We still want to win, and we still go out there with that intention."

The Giants weathered a standout performance by Colorado starter Jhoulys Chacin, who allowed just four hits and one run -- Buster Posey's 15th homer in the second inning -- through the first seven innings.

But trailing 2-1 entering the bottom of the eighth, the Giants immediately jumped on Chacin's relief, Matt Belisle. With one out, Angel Pagan hit a grounder down the third base line that was thrown away at first base for a single and error that put Pagan on second. After Marco Scutaro popped out, Belt ripped the first pitch he saw from Belisle into the right field corner and Pagan scored easily.

Then in the 10th against Colorado's fourth pitcher, Adam Ottavino, Pagan laced a one-out single to right and advanced to third on a Scutaro single. After Scutaro moved to second on defensive indifference, Belt looked for a pitch he could drive and finally got a 1-2 pitch he lifted over the head of left fielder Josh Rutledge.

"The whole at-bat I was looking for something up in the zone," Belt said. "Once I got two strikes, I just wanted to put the ball in play, I didn't care what happened. Fortunately, I squared it up."

The Rockies scored the first run of the game in the second inning thanks to some Giants' absent-mindedness in the field. Nolan Arenado doubled into the left field corner with one out, and when Yorvit Torrealba hit a chopper between home plate and the mound, catcher Posey came out to field the ball and throw to first.

But the Giants left home plate unattended on the play, and an alert Arenado sprinted home. First baseman Belt made a throw to the plate, but no one was there to cover and the ball went to the backstop.

The Giants tied the score in the bottom half of the inning when Posey homered over the left field wall. It was Posey's first home run since July 20 -- after 134 homerless at-bats -- and just his second since the All-Star break.

Colorado struck again for a run in the third when D.J. LeMahieu doubled to left field and scored on Troy Tulowitzki's single to center for a 2-1 lead.

  • Chad Gaudin and Jeremy Affeldt alternated throwing two innings apiece in a simulated outing before the game. Manager Bruce Bochy said both threw well enough that a decision about activating them will likely come Tuesday.

    Bochy didn't rule out Gaudin possibly getting a spot start before the season was done but said he hopes to keep his current rotation intact.

    Follow Carl Steward on Twitter at twitter.com/stewardsfolly.

    Tuesday's game

    Colorado (Jorge De La Rosa 16-6) at Giants (Ryan Vogelsong 3-5), 7:15 p.m. CSNBA