CHICAGO -- Joe Mather took advantage of a rare start with a go-ahead single during a three-run rally in the eighth inning Friday and the Chicago Cubs ended a four-game losing streak with a 5-3 victory over the Colorado Rockies.

The Rockies had matched a season best with a five-game winning streak.

Chicago trailed 3-2 going into the eighth before Brett Jackson led off with his second homer of the season.

Pinch hitter Luis Valbuena doubled with one out and Mather, batting in the leadoff spot usually occupied by David DeJesus, followed with an RBI single against reliever Matt Belisle (3-5).

Mather later scored on reliever Matt Reynolds' throwing error to first on Anthony Rizzo's grounder.

James Russell (6-1) got two outs for the win and Carlos Marmol closed for his 16th save.

The Rockies scored in the first on an error by shortstop Starlin Castro, a single by Jordan Pacheco and a wild pitch by Jeff Samardzija.

Chris Nelson made it 2-0 in the second with his sixth homer. Carlos Gonzalez led off the third with his 21st homer and first since July 23.

Alfonso Soriano and Welington Castillo hit solo home runs in the Cubs fifth off Drew Pomeranz, making it 3-2.

Pomeranz left after the fifth. The home runs were the only hits he allowed.

Samardzija gave up two earned runs and six hits in seven innings, striking out seven.

NOTES: Cubs manager Dale Sveum opted for Mather to lead off against LHP Pomeranz, giving DeJesus a day off. "We'll keep everybody else in their slot and see what happens," he said. "We haven't seen many lefties in a while, so we'll give Joe a few at-bats." ... Pomeranz was the first lefty starter the Cubs faced since Aug. 8 in a 2-0 loss to San Diego's Clayton Richard ... Colorado 3B coach Rich Dauer will be inducted into the Baltimore Orioles Hall of Fame on Saturday. He played for the 1983 World Series champion Orioles ... Rockies OF Dexter Fowler (ankle) is off crutches and will likely not be in the lineup during the Cubs series. He could possibly pinch hit Sunday, manager Jim Tracy said. ... Colorado INF Josh Rutledge (quadriceps) is doing better, but is heavily taped and progressing slowly and won't be pushed, Tracy said.