Colorado, which had lost eight straight before Thursday, made it two in a row in Friday's opener when Carlos Gonzalez went 4-for-6 with a home run, three runs scored and two RBI and the Rockies scored 12 times with two outs in the eighth inning to pull away from Chicago, 17-2.
The Rockies batted around twice in an eighth that saw them set club marks for runs (12) and hits (13) and the MLB record for consecutive hits (11), all while stranding the bases loaded.
"I've never seen an inning like that. We had two outs and two strikes on a hitter and they scored 12 runs. I've never seen anything like that," Chicago manager Lou Piniella said. "I feel bad for my pitchers."
Jeff Francis (4-3) was efficient in a six-inning start, allowing two runs on four hits and a walk while striking out five to pick up the win.
Towering right-hander Jason Hammel, who stands 6-foot-6, takes the mound for the hosts with an aim to end a three-start skid.
The former 10th-round pick of the Tampa Bay Devil Rays was 7-3 on the season after a 4-2 win over San Diego on July 10, but has since dropped road decisions at Cincinnati, at Florida and at Philadelphia.
He returns home to Coors Field, where he is 6-1 this season in 10 starts with a 3.18 earned run average in 62 1/3 innings.
Hammel has made one career start against the Cubs and earned a win with five innings of three-run ball with no walks and four strikeouts.
Chicago goes with lefty Tom Gorzelanny, who's won four straight starts.
The 28-year-old Illinois native recorded a save in a bullpen stint on June 24 and went 3 1/3 innings in a relief role a day later, then transitioned back to starting with five scoreless innings against Pittsburgh on June 30.
He's started and won four times since, defeating Arizona, the Los Angeles Dodgers, Philadelphia and St. Louis while allowing 23 hits and 11 runs in 23 2/3 innings.
Gorzelanny, who is 3-2 away from home in 2010, is 1-2 in three lifetime starts against the Rockies with a 10.80 ERA.
Chicago swept a two-game set from the Rockies at Wrigley Field from May 17-18, but lost three of four games between the teams held at Coors Field last season.