Zimmermann was winless in his first six career starts against the Marlins, going 0-3 with a 4.81 ERA in 33 2/3 innings against them, including a loss at Marlins Park on May 28 in which he gave up four runs on eight hits over six innings.
That wasn't the case Friday, though, as the righty reversed his fortunes against Miami in a big way.
Zimmermann, who has been arguably Washington's most consistent starting pitcher this season, was impressive as he turned in his best performance of the year, not allowing a run to cross the plate for the first time in 18 starts. It was the first time the righty didn't give up a run in an outing since Aug. 18, 2011, against the Reds.
The Marlins were unable to get much going against Zimmermann, who scattered four hits and walked just one over his six innings. Miami had one baserunner in each of the first three innings, but after a one-out walk to Jose Reyes in the third, Zimmermann zoned in, retiring the next eight hitters he faced, including five via strikeouts.
The righty sat down 11 of the final 12 Marlins he faced, allowing only a sixth-inning leadoff single to Reyes before Omar Infante and Carlos Lee each popped up to the outfield. Bryce Harper then made a diving grab in shallow center field to get Logan Morrison to end the inning and preserve Zimmermann's shutout effort.
Zimmermann has gone at least six innings in each of his 18 starts this season and he has given up two earned runs or fewer in his last six outings.
"That's what I try to do every time out there, go six, seven, eight innings," Zimmermann said. "I guess this year I've just been lucky enough to put a nice little streak together."
Friday marked Zimmermann's league-leading 16th quality start of the season, although he only has a .500 record to show for it.
"Unfortunately we never score any runs for him and he doesn't get that many wins, but he's Mr. Consistency," Ryan Zimmerman said. "You know what you're going to get out of him."
While Zimmermann was stellar, he got plenty of help on the offensive side. For the first time in his seven starts against the Marlins, the Nationals provided Zimmermann with more than three runs of support.
Ian Desmond put Washington on the board first with an RBI single in the second to plate Adam LaRoche, who finished the night 3-for-4 with two runs scored.
Zimmerman then pitched in with his ninth homer of the season, a two-run shot in the fourth to make it a three-run game. The Nationals pushed the lead to five runs in the top of the sixth when Jesus Flores came through with a two-run single that chased Marlins righty Josh Johnson and handed Miami's ace his first career loss in 16 career starts against Washington.
"He's good. He's always good," Zimmerman said of Johnson. "He's not a fun guy to face, I guess you could say. He made a mistake and I put a good swing on it."
Johnson was previously 8-0 in his career against Washington, but pitched 5 1/3 innings and gave up a career-high-tying 11 hits on Friday.
"I didn't go out there and go deep into the game and give us a chance to win," Johnson said. "Forget about those first three runs. I've got to go out there and get those last two outs, but I didn't do it."
The Marlins tried to rally in the seventh, plating a run against Henry Rodriguez on a John Buck single to put runners on the corners with one out. Michael Gonzalez got pinch-hitter Austin Kearns to hit a liner back to the mound for an easy double play to end the threat.
Five Nationals relievers helped secure the win for Zimmermann, who has been somewhat of an afterthought in Washington's rotation behind All-Stars Gio Gonzalez and Stephen Strasburg despite his consistent production each time out.
"Last year I thought he pitched like a No. 1," Davey Johnson said. "He has continued this year. ... He's grown up to me even more so this year."