Then came the seventh.
"We didn't pull off a couple double plays that were sitting right in our laps right there -- that kind of changed the game around," Cubs manager Dale Sveum said.
With the game tied, Carlos Torres singled to lead off the seventh and was forced at second on DJ LeMahieu's grounder. But the Cubs were unable to get LeMahieu at first for a double play, as shortstop Starlin Castro's throw pulled Anthony Rizzo off the bag.
"That was a lot of bad technique as much as anything," Sveum said. "[Castro] probably should've given that ball up to [second baseman Darwin] Barney in that situation."
Jordan Pacheco then singled to chase Corpas and Alex Hinshaw entered, making his Cubs debut. The lefty got Gonzalez to hit another potential double-play ball, forcing Pacheco, but Gonzalez was safe at first and LeMahieu scored on the play. Hinshaw seemed to get to first in time.
"It was a fairly hard-hit ground ball," Sveum said of Gonzalez's ball, which was fielded by Rizzo, who threw to Castro at second. "[Castro] fires it over there, and it's not the easiest one to get standing on the bag, either."
Chicago missed an opportunity in the seventh when Brett Jackson, who hit a two-run home run in the fourth, walked to lead off. One out later, pinch-hitter Joe Mather singled. Following another out, Mather was thrown out at second on a double-steal attempt.
"[Mather] didn't get a great jump off the jump I got," Jackson said. "I guess [catcher Wilin] Rosario picked it, because he picked it clean. He's got one of the best arms in baseball.
"It's tough to get thrown out right there," Jackson said. "You've got men in scoring position, and a base hit puts us ahead going into the bottom of the eighth. We were playing aggressive. Unfortunately, he picked it clean. I didn't get the best jump in the world. I think Joe was watching me. I didn't see his jump, but that's what he was saying."
Did Jackson and Mather miss a sign?
"It was missed," Sveum said. "Coach tells you not to go anywhere and you do, it was missed."
Said Jackson: "We were on our own. Nothing was put on -- it wasn't a [signal to] steal. While [Will Harris] was warming up, we talked to [first-base coach Dave] McKay about it. He said, 'He's slow to the plate,' and [he] thought we could get him."
But they didn't. Expect a refresher course on the signs on Sunday.
"This is what we talk about, about slowing the game down," Sveum said. "We have the matchup we want with [Josh] Vitters up there against a left-handed pitcher. You don't need to be going anywhere -- we had a great matchup right there."
The Rockies had a play on in anticipation of a double steal.
"It's great to execute like that," Rosario said. "When everybody knows what to do and does it, it makes us a good team."
Does Sveum hit his head against the wall when he sees mistakes?
"I might have hit it too hard, and I might not have made it the rest of the game on that one," he said.
Raley, recalled from Triple-A Iowa before the game, will stay in the rotation the rest of the season but continue to be limited to five innings each outing. The lefty, who began the year at Double-A Tennessee, has totaled 156 innings already.
"Who doesn't want to go seven, eight innings and give your team the chance to win?" Raley said. "I felt like I gave us a chance to win through five today. I understand [being limited], and I want to win as bad as anybody else. It's not going to keep me from competing."
"He got the five innings and 80-something pitches and that was enough," Sveum said.
The Cubs opened a 3-0 lead, as Alfonso Soriano scored on an error by third baseman Chris Nelson and Jackson hit a two-run homer, his second in as many games.
"I hit that homer about 367 feet, and I think the wall is 368," Jackson said. "I'll certainly take it."
This was Jackson's first multi-RBI game, and his first game since his debut on Aug. 5 that he had more hits than strikeouts.
"It's more relaxing because my swing is more comfortable and I'm having better at-bats," Jackson said. "It's not that I'm getting hits -- sure, I'm happy about that and I'm producing -- but I feel confident at the plate and we've made some good adjustments and we'll continue to work and keep trying to get better."
Seven of Jackson's 12 hits this season have been for extra bases.
"With the strikeouts and everything, right now he's got a .700 OPS," Sveum said. "It's not what you want, but with those strikeouts, he's still hit three home runs, has a couple doubles, and a triple. That's the kind of center fielder you're asking for, and when he cuts down on the strikeouts, [his OPS] will get higher and higher."
And, Sveum hopes, the kids will get smarter and smarter.