CHICAGO -- The Colorado Rockies are building for the future, and their prospects are taking advantage of the opportunity.
Colorado grabbed the lead for good when Carlos Gonzalez used his speed to beat out a potential double-play ball in the seventh inning, allowing DJ LeMahieu to come home for a 4-3 lead.
Carlos Torres (3-1) threw 2 1-3 scoreless innings as four relievers combined for five innings of one-hit ball, leading the Rockies to their sixth win in seven games.
"It's good for our kids, as young as we are," manager Jim Tracy said. "To be involved in games like this, and the realization we are playing in this type of game, there is no room for error."
Brett Jackson hit a two-run homer for Chicago, which has lost five of six and seven of nine.
"He had some good swings," Cubs manager Dale Sveum said. "That should be helping him out confidence-wise."
Jackson connected in the Cubs' three-run fourth inning against Alex White, belting a drive to centre for his second homer in two days and No. 3 for his career -- all in the last week.
Rutledge hit for White in the fifth and drove the first pitch he saw from Brooks Raley over the wall in left, trimming the Cubs' lead to 3-2. Rutledge has been out of the starting lineup since Aug. 19 with a sore quadriceps.
"Everything he's done is impressive. We're trying to nurse him along," Tracy said.
Raley, recalled from Triple-A Iowa before the game, allowed five hits, struck out four and walked three in his fourth career start.
Brown hit a tying solo shot off Manuel Corpas in the sixth. Brown hit 24 home runs in 100 games with Triple-A Colorado Springs before the Rockies promoted him on July 17. His first home run in the majors arrived in his 26th game.
"It was a nice milestone. Hopefully it's not the last," Brown said. "It was a great feeling to come through at the time.
"I'm trying not to do too much. You always press when you try to do too much to prove you can do what you've been doing. I'm finally starting to get back to trying to meet the ball square."
Corpas (0-1) was charged with two runs in 1 1-3 innings against his former team as the Cubs dropped to 5-18 in August.
Rafael Betancourt worked the ninth for his 26th save in 31 chances. He has converted nine of 10 opportunities in August.
"What we did today that we didn't do yesterday was execute late in the game to win a one-run game," Tracy said. "We took a terrific job from Carlos Torres through all the guys to (Betancourt), their aggressiveness throwing strikes."
NOTES: Reliever Alex Hinshaw made his Cubs debut when he pitched to Gonzalez in the seventh. The Cubs claimed Hinshaw off waivers from the Padres on Aug. 19. ... Chicago optioned LHP Chris Rusin (0-1, 1.80 ERA) to Triple-A Iowa before the game. Rusin is expected to return to the majors when rosters expand in September. . Rockies SS Troy Tulowitzki (groin) and 1B Jason Giambi (viral syndrome) began rehab assignments with Double-A Tulsa on Friday. Tulowitzki went 1 for 3 with a double in five innings. Giambi went 1 for 3 with an RBI. ... Sveum said he doesn't expect the team to call up many players in September. "I don't think it'll be an overwhelming amount, but just enough to help us out in September where we can do some things roster-wise during the game and pinch hit, three to four pitchers to help out," he said.