CINCINNATI -- Cincinnati Reds right-hander Scott Feldman has struggled with his breaking pitches in his past few starts. Feldman's side work with pitching coach Mack Jenkins paid off Friday night when he had Chicago Cubs hitters flailing for most of his seven innings.

Adam Duvall hit a three-run homer and Feldman tossed seven shutout innings to lift the Reds to a 5-0 victory over the Cubs in the opener of a three-game series at Great American Ball Park.

Feldman (7-5) allowed only two hits through seven innings with two walks and seven strikeouts. He held his former club hitless into the sixth inning.

"I kind of lost feel for that breaking ball especially to righties the past two or three starts, but my fastball command was better so I was getting away with it," Feldman said. "We kind of worked on it in between. It was better tonight."

Chicago (40-40) has won 23 of the past 29 meetings with the Reds but couldn't get anything going offensively without third baseman Kris Bryant, who is recovering from a sprained right ankle. The Cubs managed only three hits.

Feldman didn't allow a hit until Ian Happ's single with two outs in the sixth inning, which put runners at first and third. But Anthony Rizzo lined to Billy Hamilton in center to end the inning.

The Reds' rotation ranks last in the major leagues with a 6.29 ERA. Feldman's ERA now is 3.78.

"We're lucky to have him," Reds manager Bryan Price said. "With everything that's gone on, the one constant has been the quality of Scott Feldman."

A perfectly executed squeeze bunt by Jose Peraza allowed Duvall to score from third in the bottom of the sixth, increasing the Reds' lead to 4-0. It was the second successful squeeze by Cincinnati this season.

"I'm not a part of too many of those," Duvall said. "It gets your adrenaline going and your blood pumping."

Cubs starter Mike Montgomery (1-5) made his fifth start since being moved into the rotation and allowed four earned runs and nine hits in 6 2/3 innings. He walked two and struck out seven.

Cincinnati (34-45) scratched across another run in the eighth when Joey Votto doubled for the second time in the game, stole third and scored on catcher Victor Caratini's throwing error. Caratini was making his first major league start.

"He did a real nice job," Cubs manager Joe Maddon. "I thought he had a good way about it, he was not overwhelmed by anything. He caught a good game."

Montgomery allowed three straight hits to begin the fourth inning, one a double by Hamilton, who was thrown out trying for a triple by center fielder Albert Almora Jr. as Javier Baez made a lunging tag.

With runners on second and third, Duvall lined a 1-1 changeup from Montgomery to the opposite field for a three-run homer, putting Cincinnati ahead 3-0. It was Duvall's 19th home run this season.

"I thought I did a good job early," Montgomery said. "I made one mistake to Duvall, left it out and over. They just had some of those hits where I didn't make a bad pitch, they just hit it where we weren't."

Montgomery needed 31 pitches to get through the fourth, in which he allowed three runs and five hits with a walk.

Feldman, meanwhile, allowed no hits with two walks and five strikeouts through five innings. The Cubs didn't come close to a hit aside from Caratini's bloop to left in the fifth inning that landed a foot foul.

"He took advantage out of our aggressiveness and really got us to chase a lot out of the zone," Maddon said. "He knew what he was doing. He used our aggressiveness against us."

NOTES: Cincinnati reinstated SS Zack Cozart from the 10-day disabled list and optioned RHP Kevin Shackelford to Triple-A Louisville. ... The Reds announced RHP Jackson Stephens will start Saturday in his major league debut. ... Cubs 2B Ian Happ starred at the University of Cincinnati. ... Cubs RHP Kyle Hendricks played catch from 120 feet. He's expected to throw off the mound at Wrigley Field on Tuesday or Wednesday. … Cincinnati is the only team in the major leagues with three players who have 19 or more home runs (Joey Votto 23, Scott Schebler 20, Adam Duvall 19).