Chris Nelson stole home in the eighth inning to send the Colorado Rockies to a 6-5 victory over the Cincinnati Reds on Thursday, completing a four-game series sweep and extending their winning streak to season-best seven games.

With one out and runners on the corners, Reds reliever Nick Masset (3-4) thought Colorado was going to try a double steal so he stepped off the rubber and whirled to second. Nelson broke for home on the play and scored easily, giving the Rockies a 6-5 lead.

Huston Street allowed a leadoff single to Ramon Hernandez in the bottom half, then struck out the side for his 17th save in 21 save opportunities.

Drew Stubbs hit a two-run homer in Cincinnati's four-run second, helping the Reds build a 5-0 lead. But Colorado chipped away at the deficit against starter Travis Wood then broke through against the Reds' bullpen.

Jason Giambi hit a two-run homer in the fourth, Dexter Fowler added an RBI double in the fifth and pinch-hitter Jonathan Herrera drove in a run with a grounder in the seventh, making it 5-4.

Colorado almost went in front in the seventh but left-hander Aroldis Chapman got MVP candidate Carlos Gonzalez to ground into an inning-ending double play with the bases loaded. Gonzalez grounded a 103 mph fastball right to shortstop Paul Janish.

Masset entered to pitch the eighth and Troy Tulowitzki led off with his 18th homer and sixth in seven games. Giambi followed with a walk and was replaced by Nelson.

First baseman Joey Votto, also in the running for MVP award, then made a critical error on Melvin Mora's slow bouncer. He charged the grounder, but his underhand flip to Masset covering first was high and wide. Nelson went to third on the play, setting up the 15th swipe of home in Rockies history and first since Matt Holliday in 2006.

The Rockies have won 10 straight games against the Reds at Coors Field dating to Aug. 23, 2008, and 19 of their past 22 games overall against Cincinnati, including 14 of the past 17.

Matt Belisle (7-5) recorded two outs to get win.

Cincinnati got off to a nice start against Jason Hammel, who pitched seven innings. Brandon Phillips singled, stole second and advanced to third on a wild pitch before scoring on Votto's swinging bunt in the first.

Hernandez hit an RBI double and scored on Janish's single in the second. After Wood sacrificed, Stubbs hit his 16th homer and first since Aug. 14.

NOTES: Rockies LHP Jeff Francis will start Monday against the Padres in place of injured Aaron Cook. ... Reds SS Orlando Cabrera was given the day off as a precaution after playing three games following a month on the disabled list with a strained left oblique muscle. ... Reds OF Jay Bruce (right side strain) took batting practice, but manager Dusty Baker said Bruce was not ready to play yet. ... Rockies 1B Todd Helton, who has one hit in his past 22 at-bats, was given a planned day off following a night game.