CINCINNATI

Bronson Arroyo limited the NL’s most prolific offense to four singles in eight innings, and Jay Bruce had a two-run homer among his three hits, leading the Cincinnati Reds to a 3-0 victory over the Colorado Rockies on Monday night.

The Reds have three shutouts in their last four games. They’ve blanked out six of their last 21 opponents, tying them with St. Louis and Pittsburgh for the league lead with nine shutouts this season.

Arroyo (6-5) allowed only one runner to reach second base while throwing 86 pitches. Aroldis Chapman gave up a walk and fanned three in the ninth, getting his 15th save in 17 chances.

Bruce scored on Todd Frazier’s single in the fourth inning off Tyler Chatwood (3-1) and hit his ninth homer off left-hander Josh Outman in the eighth.

The Rockies’ pitching staff had a setback for the second day in a row. Chatwood left with a sore triceps after pitching only four innings. Rockies closer Rafael Betancourt went on the 15-day disabled list over the weekend with a strained groin.

“We wanted to leave him out there, but he was feeling it, especially on his fastball,” manager Walt Weiss said. “It’s the first time he’s ever felt anything there.”

Chatwood (3-1) batted in the fifth, bunted and was thrown out. Rob Scahill had been throwing in the bullpen and replaced Chatwood, who threw 64 pitches and allowed four hits and one run.

Colorado took him out as a precaution to get treatment. It’s unclear whether it will force him to miss a start.

“They seem to think it’s not serious, just a little inflammation,” Chatwood said. “I’ve had soreness, but I’ve never had this kind of soreness. It was a little different.”

The right-hander was coming off one of his noteworthy starts. He fanned a career-high 10 in six innings against Houston.

“It’s frustrating to come out of the game like that when you’re feeling good and leave your bullpen hanging like that,” he said. “It was a precautionary thing and hopefully everything will be all right.”

Arroyo came in with a 4-8 career record against the Rockies but kept them off balance from the start. His first three pitches of the game clocked 70, 72 and 72 mph. His pitches occasionally dipped to 69 mph.

“I didn’t have amazing stuff,” Arroyo said. “Things just worked out. It was one of those games. I was able to keep guys off second base. Had some quick innings, kept my pitch count down. Some days the ball bounces your way.”

The Rockies lead the NL in runs but couldn’t do much with those many oh-so-slow deliveries.

“He’s tough, Arroyo,” Weiss said. “He’s good at reading swings and going back and forth and changing sequences and speeds.”

The Reds have gone only 3-3 in the past week because of a slumping offense. They used a couple of well-placed hits to get a run in the fourth.

Bruce went the opposite way to left field, beating Colorado’s infield shift, for a single with two outs. He stole his first base of the season and came around when Frazier flicked a low-and-away pitch to left field, one hand leaving the bat as he made contact. Bruce scored as Carlos Gonzalez’s throw to the plate hit him in the back.

Zack Cozart singled in the eighth ahead of Bruce’s homer, extending his hitting streak to a season-high eight games.