Billy Hamilton had three hits, scored twice and was at the center of two pivotal replay reviews that went the Reds way and also figured in the win.
Cueto's pitching, however, was the most prominent factor.
"He knew that he needed to step it up because the last couple starts, they weren't too good for him," Reds catcher Brayan Pena said. "He said, `Pena, today you're going to see something different. I'm going to be me.' And that's exactly what he did. When he's on, he's a game-changer."
Cueto (7-6), whose name has come up repeatedly in trade-rumors, put on a dominating display in hitter-friendly Coors Field, limiting the power-hitting Rockies' lineup to four singles before being lifted for a pinch-hitter in the ninth. He struck out five and walked one in a performance sure to heighten attention ahead of the July 31 trade deadline.
"He's one of the best pitchers in the business, one of the best I've faced this year," Rockies slugger Carlos Gonzalez said. "He's one of those guys that you won't feel very comfortable (facing) at the plate because if you try to do too much he's really smart and he will get you out quick."
Cueto will find out in the coming days whether it was his last start for the Reds.
"Everytime I come to the ballpark, I feel like this is the last time," Cueto said through an interpreter. "My teammates are feeling the same way. Something is going to happen. They're going to trade me, so I don't know what's going on."
Chris Rusin (3-4) allowed five runs and 10 hits in five innings.
The Reds batted around in the third to take a 4-0 lead behind Joey Votto's RBI single and the three-run shot by Frazier -- the winner of the home run derby during All Star game festivities at his home park. It was Frazier's 27th of the season.
Hamilton, the major league leader in stolen bases, triggered the Reds' big inning when he singled to lead off the third. Initially called out, a reply review showed he beat the ball to the bag.
In the fifth, he manufactured another run, singling up the middle and then flashing his speed on the bases.
"Hamilton creates some havoc with his speed. We had a hard time containing him," Rockies manager Walt Weiss said.
Rusin threw to first in an attempted pickoff but Hamilton was already headed to second, forcing a hurried and errant throw by first baseman Ben Paulsen that went into the outfield, allowing Hamilton to advance to third. He scored on Votto's groundout after initially being called out at home. The Reds challenged and the replay showed Hamilton got in ahead of the tag.
Rockies: RHP Christian Bergman pitched a simulated game (35 pitches) Saturday in the latest step toward returning from right shoulder inflammation that landed him on the DL late last month. He's slated to pitch a simulated game (45 pitches) Tuesday for Triple A Albuquerque as part of a minor league rehab assignment. ... Nolan Arenado was lifted for pinch-hitter McKenry in the ninth after being hit by a pitch on the top of his left hand in the seventh inning. X-rays were negative and a team spokesman said Arenado was day to day with a hand contusion.
Reds: Rookie RHP Michael Lorenzen (3-4) beat the Rockies the first time he faced them on May 26. He'll try for a repeat of that performance in the series finale.
Rockies: RHP Kyle Kendrick, an offseason free-agent acquisition, makes his 10th start this season at Coors Field, where he has gone 1-5 with a 6.89 ERA.
- Home Plate Umpire - Bob Davidson
- First Base Umpire - Hunter Wendelstedt
- Second Base Umpire - Marvin Hudson
- Third Base Umpire - Pat Hoberg