O'Grady's craftiness played well against Cincinnati hitters, who entered hitting an MLB-low .210 in the second half. The rookie southpaw turned in the best outing of his career, tossing seven scoreless innings while striking out five and walking two en route to his second victory.
"I think he had better command today," Marlins manager Don Mattingly said. "He was having some trouble with his command over in Cincinnati, he got himself in trouble. For him to be successful, he's gonna have to be able to command the ball, throw strikes when he wants, throw balls that look like strikes that end up being balls, he needs to be able to do that off the edges. And I thought he was able to do that."
The Reds left 12 men on base in the game, including seven with O'Grady pitching. It was the eighth time in 14 second-half games Cincinnati was held to two runs or fewer.
"I think we had about 11 balls in play hard over the course of the game, several baserunners, and didn't do anything with those opportunities, unfortunately," Reds manager Bryan Price said. "We just haven't run into a couple of guys in the lineup that can really do the damage we need to have done. We had some RBI opportunities that just never came to fruition."
Robert Stephenson walked a career-high seven batters during his 4 1/3 innings. He allowed three earned runs, the last two of which came after Drew Storen entered for him in the fifth, then walked Dietrich with the bases full and yielded a sacrifice fly to Tyler Moore.
Junichi Tazawa allowed an eighth-inning RBI single to Scooter Gennett, but Marlins closer AJ Ramos came on for four outs to earn his 20th save.
"We've been talking about it for a while, actually from Spring Training, that we would use [Ramos] like that," Mattingly said. "I felt confident with [Tazawa], but I felt like I know AJ was strong and he bounces back."
MOMENTS THAT MATTERED Dietrich drives 'em in: A night after notching a career-high five RBIs in Miami's 22-10 win over the Rangers, Dietrich didn't waste time driving in more. The second baseman launched a solo shot in the fourth off Stephenson to give Miami a 1-0 lead. His fifth long ball of the season traveled a projected 397 feet and had an exit velocity of 104 mph per Statcast™. After Dietrich's RBI walk in the fifth, he blooped a single to score Christian Yelich and tack on Miami's fourth and final run.
"We got enough to win tonight and that's all that matters," Dietrich said. "It was a good night. Long night yesterday, so to come out there and win a ballgame is a good way to start a homestand."
Tagged out: With a chance to tie the game at one, Reds third base coach Billy Hatcher waved Joey Votto around third on Adam Duvall's two-out double in the fifth. Marlins left fielder Marcell Ozuna fished it out of the corner and fired to Miguel Rojas, who skipped a one-hopper home to nab Votto. Not known as a speedster by any means -- and rated by Statcast™ as being tied for the slowest sprint speed on the Reds -- Votto tossed his helmet in frustration after the tag.
"A lot of things have to happen and obviously it's a bang-bang [play] at the plate," Mattingly said. "When you talk about a game of inches, that's where if the ball bounces just a little bit, or Ozuna's throw takes Miggy off where he can't stay on balance and get rid of the ball quickly, a lot of things have to happen positively and they all do on that play."
WHAT'S NEXT Reds:Sal Romano (2-2, 5.50 ERA) will face the Marlins in consecutive starts when he pitches against Miami at 7:10 p.m. ET on Friday. Romano pitched very well in a 6-3 victory on Sunday with six innings, one earned run, three hits, one walk and seven strikeouts.
Marlins:Vance Worley (0-2, 6.37) makes his first start since June 9 in place of the recently optioned Tom Koehler, as the Reds and Marlins continue the series.