Ricky Nolasco was hurt by the bottom of the Washington order. Specifically, Kurt Suzuki created problems for the Marlins' ace, who was tagged for four runs with six strikeouts in six innings.
Suzuki collected a home run and a triple. The Nationals' catcher drove in two runs and scored twice to help his team take two of three in the series.
Miami concluded a 2-7 homestand, and now is 3-12 heading into Cincinnati for four games beginning on Thursday night.
"The main thing is we've got to stay positive," said Nolasco, who for the first time in his career has begun a season with four starts and is without a victory. "As starters, we've got to keep doing our thing. As a team, we've just got to help each other out as much as we can, and try to pull the whole thing together. I'm confident we'll be able to do that. I'm looking forward to the road trip. Maybe we'll be able to turn things around."
Along with Suzuki, Bryce Harper also gave Nolasco problems, going 3-for-3 with a double and a run scored. For the season, Harper is 5-for-6 off Nolasco with two home runs. For his career, Harper is now 9-for-20 against the Miami right-hander.
"Now, it is to the point where I make good pitches and they're still falling," Nolasco said. "I just hope he just doesn't turn into Chipper Jones for me, where every time I break his bat or make good pitches, they're still hits. I'm going to be seeing him a lot. We'll be facing each other a lot. I'm looking forward to the challenge of stepping my game up and getting him out more than he gets me."
The now-retired Jones batted .341 in his career off Nolasco.
Detwiler entered the game having allowed one earned run in 13 innings this year. Miami played without shortstop Adeiny Hechavarria, who was scratched due to a sore right elbow, and struggled to get anything going against Detwiler, who has an 0.90 ERA.
"He's probably one of the best, obviously," Miami manager Mike Redmond said of Detwiler. "If you look at his numbers, they're pretty good, which is an understatement.
"I like his approach. He just goes up there and pounds the zone with fastballs. He threw just a handful of breaking balls. But he moves that ball in and out. He has enough movement to keep guys off balance. We didn't have a whole lot of good swings off him. He did a nice job."
Chris Valaika started in place of Hechavarria, and he delivered a double off Detwiler, and later scored Miami's lone run.
After falling behind by three runs, the Marlins pushed across a run in the fifth inning on Donovan Solano's two-out RBI single to right. In a season where not much has gone their way, the Marlins did catch a break on the play.
Valaika, who doubled to lead off the inning, scored on a bang-bang play at the plate. Right fielder Jayson Werth made a strong throw home, and Suzuki lunged to apply the tag. TV replays showed Valaika was tagged on the helmet just before his right hand swiped the plate.
Home-plate umpire Greg Gibson ruled safe, as Suzuki and Nationals manager Davey Johnson protested.
"[Detwiler is] definitely not [a typical fifth starter]," Johnson said of his left-hander. "He's got great stuff, and he locates it. He uses both sides of the plate as good as anybody I've seen, and his fastball's explosive out of his hand. He didn't use his changeup, but he's got an above-average changeup to go with the curveball. He's still in the learning stages. He's awfully good just right where he's at."
Two singles and a disputed stolen base led to Nolasco giving up two runs in the second inning. Adam LaRoche and Ian Desmond strung together successive singles to open the inning. With runners at the corners, Desmond swiped second, but not without a little controversy. Miguel Olivo made a strong throw and shortstop Valaika had the ball awaiting Desmond's slide. But umpire Alan Porter signaled safe, prompting Redmond to trot out to second for an explanation.
"I felt like I threw the ball well," Nolasco said. "Didn't catch a couple of breaks there. I felt we had Desmond at second, that could have eliminated damage. I thought I did a good job of just working out of that, and not giving up another hit."
Roger Bernadina tapped an RBI groundout to shortstop in the second inning, and Suzuki lifted a sacrifice fly to center, giving Washington an early edge.
Suzuki provided an even bigger blast in the fifth inning, a full-count home run to left field. The blast, his second of the season, came one pitch after he shattered his bat on a foul ball.
The Nationals tacked on a fourth run in the sixth inning on LaRoche's RBI single, capping the scoring off Nolasco. In the seventh inning, Suzuki tripled off Ryan Webb and scored on Steve Lombardozzi's one-out single, and Harper's infield single in the ninth plated Werth with Washington's final run.
"I thought Ricky did a nice job," Redmond said. "He kept us in the game. Everything is magnified right now because we're just not able to put a big number up on the board. Everybody has to pitch perfectly. That's tough to do in this league."