CINCINNATI — Aaron Cook ended his road futility at the place he still calls home.

Cook went seven innings for a breakthrough win on the road Sunday, and Chris Iannetta’s homer off left-hander Travis Wood gave the Colorado Rockies a 1-0 victory over the Cincinnati Reds, who are losing a lot of those minimal games these days.

Cook (4-5) gave his best performance of the season in a ballpark that’s only a half-hour drive from his hometown of Hamilton, Ohio. With family in the stands, he allowed only six hits and one unintentional walk in seven innings.

“It was by far and away his best performance of the year,” Rockies manager Jim Tracy said. “It was vintage Aaron Cook.”

The right-hander had been one of only four full-time NL starters without a road win this season, going 0-5 with a 6.70 ERA away from Coors Field. All that changed back in his old stomping grounds.

“This is where I grew up,” Cook said. “It always feels like home when I come back. I feel comfortable pitching here. There’s something about it.”

Two of the NL’s top offenses had trouble on a hot, breezy afternoon — the kind that usually means a lot of runs at Great American Ball Park. This one was decided by one swing.

Iannetta connected in the sixth on a changeup that was over the plate but down.

“I threw a pretty good pitch,” Wood said. “He just put a good swing on a good pitch, and it went out.”

The Reds wasted a chance to tie it in the ninth against closer Huston Street, who pitched out of a two-on threat. The final number was numbingly familiar — Cincinnati has lost five 1-0 game this season. Each of its last three losses have been by the same score.

“These 1-0 games are killing us,” manager Dusty Baker said. “It seems like lately we score a lot of runs or none at all.”

They had a chance in the ninth against Street, who gave up one-out singles by Drew Stubbs and Ryan Hanigan that put runners at first and third.

Street knew he had to get strikeouts, and used his slider to fan Chris Heisey and Brandon Phillips.

“The last eight pitches were sliders,” said Street, who is 6 for 6 in save chances since returning from a sore shoulder.

Colorado has piled up big numbers at Coors Field but struggled on the road, batting only .231 — third-worst in the majors. That trend held: Colorado scored only four runs while dropping two of three during the series.

The struggles on Sunday had a lot to do with Wood, a 23-year-old rookie who was nearly perfect his last time out. The left-hander retired the first 24 Phillies on July 10 before Carlos Ruiz led off the ninth with a double — the only runner to reach against him. Philadelphia eventually won it 1-0 in 11 innings.

Iannetta had two of Colorado’s three hits off Wood.

“Those were not comfortable at-bats,” Iannetta said. “He has a lot of movement on all of his pitches.”

Wood (0-1) struggled with his control, but was adept at pitching out of trouble. He walked a pair in the second inning, when a double play bailed him out. The Rockies loaded the bases in the fourth, but Wood got Clint Barmes to pop out.

The Reds trumped them in futility, leaving runners in scoring position in each of the first four innings. That’s been a trend — Cincinnati is 3 for 35 with runners in scoring position over the last five games.

NOTES: Colorado also won a 1-0 game June 12 against Toronto. … The Rockies are 1-2 at the start of an 11-day trip, their longest of the season. … 2B Jonathan Herrera went 0 for 4, ending his hitting streak at 13 games. RF Carlos Gonzalez had his streak stopped at 10 games. … Reds 3B Scott Rolen was out of the lineup for a second straight day because of illness. … The Reds were shut out for the 11th time.