CINCINNATI -- Trevor Williams and Joe Musgrove both knew they were going to pitch on Sunday afternoon at Great American Ball Park -- Williams to start and Musgrove in relief. So on Sunday morning, they came up with a plan.

“Let’s be good today, but let’s not be too good,” Williams said, “because then they might fall in love with that Williams-Musgrove combo.”

They were good, but don’t expect the Pirates to begin piggybacking their starters anytime soon -- not after Williams picked up right where he left off last season in the Pirates’ 5-0 win over the Reds to wrap up the rain-abbreviated two-game series.

Making his season debut after a spectacular second-half run in 2018, Williams held the Reds to three hits and struck out six over six innings on the mound. He chipped in at the plate, too, knocking an RBI single to right field and drawing a bases-loaded walk against Reds starter Sonny Gray.

The run production might have been a surprise, but nobody was caught off guard by the way Williams pitched. The right-hander did it routinely during his final 13 starts of last season. He started nine of the Pirates’ 16 shutouts last season, and he was the only pitcher in the Majors to make 10 starts of at least six scoreless innings. Sunday brought more of the same.

“It was incredible. We didn’t expect anything less from him,” Musgrove said. “We talk about the season he had last year. You can’t really go out there and expect yourself to do the same thing. I think he has higher expectations.”

Williams needed only 80 pitches to get through six innings. He kept Cincinnati’s dangerous lineup in check primarily with his fastball, which got him out of the only jam he encountered in Pittsburgh’s first win of the season.

Joey Votto hit a two-out single in the sixth to put runners on the corners and bring up Yasiel Puig, representing the tying run. Williams fired three straight fastballs to Puig, the last one a 92-mph pitch above the strike zone. Puig went down swinging, and Williams marched off the mound with a 3-0 lead intact.

“He has a lot of confidence in his fastball, and we’ve got confidence in him throwing his fastball. There’s no reason not to,” Pirates manager Clint Hurdle said. “When he can get it spotted up where he wants it to go, it makes it a different dynamic for the other pitches to play.”

Williams introduced a new wrinkle during Spring Training, making more use of the curveball he only threw six times last season. He used two on Sunday, one which struck out Jose Peraza in the fifth inning. The whole point of that pitch, Williams said this spring, was to turn a potential 5 2/3-inning outing into a six-inning start. It played out that way in his season debut.

“It got me an extra out,” Williams said. “It got me an extra punchout.”

Williams also got the best of Gray at the plate. With Melky Cabrera on second base and one out in the second, Williams poked a single down the right-field line for his second career RBI -- his first since his first Major League start on Sept. 17, 2016.

Pittsburgh loaded the bases in the third with a Francisco Cervelli single and walks by Jung Ho Kang and Erik Gonzalez. Up came Williams, who took five pitches to force in another run.

Williams was scheduled to start on Saturday before that game was rained out. The postponement pushed back , who was originally scheduled to start Sunday, but Musgrove volunteered to be flexible and pitch out of the bullpen in Sunday’s series finale.

The Pirates took him up on it and called on the right-hander to work two innings in relief.

“I just wanted to pitch. You prepare all week for a start day. To have it completely taken away would have sucked,” Musgrove said. “I’m glad I got to go out there and at least get some work in.”

Musgrove said his stuff wasn’t particularly sharp, but he was nonetheless effective. He needed only 30 pitches to retire all six hitters he faced in the seventh and eighth innings. Closer Felipe Vazquez recorded two outs in the ninth, and Keone Kela struck out Matt Kemp to finish it.

“Just a good day of baseball for us. All-around team effort,” Hurdle said. “We caught it on defense. We pitched it extremely well. We were continually putting pressure on the other team from the offensive side.”