CINCINNATI -- The Cincinnati Reds knew they were getting a quality pitcher when they acquired right-hander Luis Castillo in a trade with the Miami Marlins in January. But the 24-year-old has exceeded most expectations and now appears penciled into the Reds' rotation for 2018.

On Wednesday afternoon, Castillo allowed one run with a career-high 10 strikeouts in his final start of the season, lifting Cincinnati to a 7-1 victory over the Milwaukee Brewers in the finale of a three-game series at Great American Ball Park.

"We knew what we were getting stuff-wise," Reds manager Bryan Price said of Castillo. "He's a tough kid. Hard worker. Tremendous confidence. He's the real deal."

Castillo (3-7) retired 22 of the last 24 batters he faced during his eight-inning stint. He threw 111 pitches on Wednesday, his second-most this season.

"After the first inning, he eliminated their ability to get the barrel on the ball," Price said. "He was outstanding. How many guys can come up from Double-A and do what he's done?"

Among his seven losses, Castillo (3-7) twice was the victim of blown saves and absorbed a 1-0 loss to Pittsburgh.

Price confirmed earlier in the week that this was Castillo's final start. He finished with 169 1/3 innings between Double-A and the majors this season. Castillo had 131 2/3 innings in the minors last year.

"I feel really happy that I had a great year," Castillo said through a translator. "I'm going to take this offseason, go back to the Dominican, and work hard."

Zack Cozart and Jose Peraza each homered for the Reds (61-79), who swept the Brewers for the first time since May 10-12, 2013, at Great American Ball Park.

"They outplayed us," said Brewers manager Craig Counsell. "We didn't have a good series. Today, we ran into a good pitching performance. We didn't get anything going against their starting pitching."

Neil Walker hit a solo home run for Milwaukee (72-68), which has lost four of its past five games and trails the first-place Chicago Cubs by four games in the National League Central standings.

The Cubs played at Pittsburgh on Wednesday night. Milwaukee begins a three-game series against the Cubs at Wrigley Field on Friday.

Perhaps, Milwaukee was looking ahead?

"We had good energy every day before the games," Counsell said. "It's something I was aware of. We've struggled holding this team down offensively. We knew going in that they could score some runs."

Milwaukee collected only four hits off Castillo -- two in the first inning.

Castillo struck out three batters in the first but also allowed Walker's 13th home run of the season to open the scoring.

It was the first and only lead for the Brewers in the series -- and that was all the offense Milwaukee could muster against Castillo.

"They're a really good team," Castillo said. "I just wanted to compete and make my pitches. I had really good command."

Brewers starter Matt Garza (6-9) allowed five earned runs on six hits over 2 2/3 innings.

The Reds collected three consecutive singles in the third, including an RBI hit by Adam Duvall to tie the score at 1.

A fourth straight hit loaded the bases with one out and Garza walked Scott Schebler to force in the go-ahead run.

"Matt just had some bad luck," Counsell said. "I don't think he had too many pitches he wished he had back -- maybe the walk to Schebler. They had some jam shots and the double play we couldn't turn. I thought he pitched OK."

Walker couldn't handle Hernan Perez's throw to complete a potential inning-ending double play on Peraza's grounder, allowing two more runners raced home giving the Reds a 4-1 lead.

Cozart collected his 18th home run, a solo shot off Jeremy Jeffress in the seventh inning. Peraza homered off Corey Knebel in the eighth.

"It sucks, but we still have three weeks left," Garza said. "We can turn it around and get back in this thing. We've got the off day tomorrow to regroup and get right back at it."

NOTES: Reds CF Billy Hamilton left the game in the third inning with a fractured left thumb, which isn't necessarily season-ending. ... Reds recalled RHP Luke Farrell from Triple-A Louisville on Wednesday. Farrell is the son of Boston Red Sox manager John Farrell. ... Reds RHP Sal Romano will start Sunday against the New York Mets at Citi Field. His turn in the rotation was pushed back due to a cut on his right index finger. ... Brewers RHP Taylor Williams made his major league debut in the eighth inning, retiring both batters he faced.