Matt Holliday, who leads the Rockies in batting (.347), home runs (10) and RBIs (43), was replaced in left field by Ryan Spilborghs in the fifth. The Rockies later announced Holliday had suffered a "head contusion" in the dugout.
Manager Clint Hurdle said Holliday suffered a "bump." Teammate Todd Helton described it as a "cantaloupe, grapefruit," but no official details emerged.
The Rockies' efforts would have been more, fruitful had they taken advantage of any of their scoring chances.
"First, third, sixth, seventh, eighth inning, we were a big hit away form breaking something open, and never got it," Hurdle said.
The Reds' Ken Griffey Jr. knocked his 575th career home run, a solo shot in the first inning, and Alex Gonzalez added a two-run homer in the fourth. Both came against Taylor Buchholz (2-3), who gave up four runs on six hits in 6 2/3 innings.
During the recent winning streak, Hurdle noted, the Rockies didn't knock a huge number of hits, but came up with big ones.
In the last three games, the Rockies have not come through against a hodgepodge of little-known hurlers -- converted reliever Todd Wellemeyer and Brad Thompson of the Cardinals, and the Reds' Livingston (1-0), who was making his second Major League start and fifth appearance.
Helton described Livingston as "crafty," but said the Rockies didn't handle key situations well.
"We're not where we should be," said Helton, who had been hitless in 10 at-bats before going 2-for-5 Friday night. "We're kind of putting a little too much pressure on ourselves.
"I think it just takes one big hit and it'll start all over again."
Livingston yielded seven hits. He forced a Holliday popup and a Helton groundout after facing runners at the corners with one out in the third. The run didn't score until he was out of the game in the seventh.
Gonzalez, playing shortstop, had the ball slip out of his hand after fielding Helton's bases-loaded grounder with two down in the seventh. Jeff Baker, who went 1-for-4 while replacing slumping third baseman Garrett Atkins, grounded out to end the inning.
Rockies center fielder Willy Taveras returned from missing three games with a lacerated right index fingernail, and went 3-for-5, including an RBI single in the eighth.
But the inning ended with two on base when Troy Tulowitzki launched a line drive to that Reds center fielder Norris Hooper snagged on the run. The Reds' David Weathers wound up with his 11th save.
"We all had pretty good ABs [late in the game], getting on base, drawing walks," Tulowitzki said. "This was one of those games where we needed big hits and we didn't get them."