Harang (4-13), who gave up six hits and three walks with four strikeouts, left with an 8-0 lead.
"I just stayed back and tried to execute my pitches as best I could and go right at them," Harang said. "I didn't go out there and try to nitpick. I was out there being aggressive, going right at them and made them put the ball in play."
But like everything else for the right-hander, the win didn't come easy. The Reds' bullpen, including Gary Majewski and David Weathers, surrendered five combined runs in the seventh and eighth innings.
Francisco Cordero gave up two ninth-inning hits and had the tying run up before notching his 25th save.
"It's never easy in this ballpark," Reds manager Dusty Baker said. "I was thinking on the bench tonight that I managed 90-95 games here in this place over my career, and you never feel comfortable until the last out, no matter what the score is."
As for the Reds' lineup, it scored as many runs in the fourth inning (four) as it did in the previous three-game series at Chicago. For a Cincinnati team that dropped 19 of its past 25 games, this was a nice one to get considering Colorado was hot with wins in five of its previous six games.
Harang was vulnerable to potential big innings multiple times, but dug in and prevented any runs from crossing. He issued a leadoff walk to start his night, but retired the rest of the first inning in order. He had runners on the corners and one out in the second and allowed a leadoff double in the third. Both times, he escaped cleanly.
It got much dicier in the Rockies' fifth, when three straight singles had Harang facing the heart of the order with the bases loaded and no outs. But he got Matt Holliday to hit a broken-bat popup and struck out Brad Hawpe with three consecutive 93-mph fastballs. Down 1-2, Garret Atkins chased an 84-mph slider for strike three, as the 30,337 fans booed the end of a rally.
"He did his job -- especially seeing him get out of those jams was a beautiful thing," Phillips said.
"He was dealing tonight," Baker said. "I was so glad to get him that win. It's been a long, long time. I'm glad we held on."
In his previous two starts since returning from the forearm injury that put him on the disabled list, Harang was 0-2 with a 19.64 ERA (16 earned runs over 7 1/3 innings).
Phillips' homer, his 21st, put Rockies starter Livan Hernandez in a first-inning hole. But it was the five singles in the four-run fourth that sent Hernandez to the showers.
The rally started with a leadoff bloop single to left field by Joey Votto, followed by an Edwin Encarnacion single to left field. Jay Bruce lined a RBI single into left and snapped Cincinnati's 0-for-15 skid with runners in scoring position. With the bases loaded and one out, Harang's groundout scored another run. Chris Dickerson's sharp roller up the middle drove in two more runs and made it 6-0.
Despite the jams on Friday, the neck spasms and the recent run of struggles, Baker stayed with Harang for the sixth and he finished with 115 pitches.
"Even though he was getting beat up pretty good, we had to get his endurance up," Baker said. "He seemed like he wasn't fazed by that many pitches. He wasn't tired. He wasn't breathing hard."
While taking an extra day to get his neck right with the help of some pummeling by a chiropractor, Harang appeared to have also straightened out some of his mechanics.
"I feel a lot better," Harang said. "We worked on some stuff this week. Mechanically, I was getting out in front of myself instead of keeping my weight back. I stayed back on the rubber. We figured out some stuff with the timing of my hands. It seemed to work."