Jhoulys Chacin threw 6 2/3 shutout innings to spoil Jon Lester’s return to Coors Field as the Colorado Rockies upended the Boston Red Sox 2-1 on Tuesday night.

Lester (8-3) last pitched at Colorado during Game 4 of the 2007 World Series, when he helped the Red Sox complete a sweep of the Rockies. The Boston lefty went six innings in his second career outing against Colorado. He allowed one run on six hits and one walk, while striking out six.

Colorado got on the board in the fifth when Todd Helton’s singled plated Chris Nelson. The Rockies added some insurance in the eighth, courtesy of a RBI single by Ryan Spilborghs.

Lester only had one hiccup, but still suffered the loss as his offense couldn't capitalize on the chances given by Chacin.

The 22-year-old Chacin allowed four hits and five walks in his 20th career appearance. He struck out five as well to improve his record to 4-6.

Chacin left with two outs in the seventh and Boston threatening with the bases loaded, but reliever Joe Beimel got pinch-hitter David Ortiz to ground out to second and end the threat.

Boston also had the bases loaded in the third, but Chacin escaped the inning without any harm.

The Red Sox cut the lead to 2-1 in the ninth when Mike Cameron’s single brought in Adrian Beltre, but reliever Matt Belisle hung out to notch his first save of the season.