Zimmermannn (6-1) scattered seven hits and struck out seven over seven innings, lowering his season ERA to 1.59. Rafael Soriano (SV 11) pitched a scoreless ninth to nail down the save.
Tigers' starting pitcher Anibal Sanchez (3-3) was tagged with the loss, allowing three runs, two earned, eight hits, striking out eight over six innings.
Harper supplied the most of the offense for the Nationals with two RBI, but Denard Span, Adam LaRoche and Danny Espinosa each chipped in with two hits.
Miguel Cabrera had the lone Tigers RBI. Jhonny Peralta was the only Tiger with two base hits, reaching base three times.
The game started 57 minutes late due to a rain delay. The Tigers would have preferred the game had never started, as Zimmermann was dominant from the get go.
Both teams made first inning base running blunders to nip any sort of rally in the bud.
Top of the inning, Torii Hunter reached on an error, but was doubled off on Cabrera's line shot to short.
Bottom of the inning, former Twin Span led off with a "Twins Hit" single, then was picked off by Sanchez.
Leading off the second, Prince Fielder hit a towering fly ball off the scoreboard in right for a stand-up double. Harper had a chance to make a leaping catch, but after crashing into the same wall last week, he looked to not want any part of the scoreboard.
Zimmermann would get the next two Tigers before walking Alex Avila. But the Tigers couldn't convert on the opportunity, Omar Infante bouncing into a fielder's choice.
The Nationals put together their own scoring opportunity in the bottom half of the inning, only to have the lack of a DH help end the threat.
LaRoche singled with one down. With two down, Espinosa laid down a perfect bunt for a single, then Kurt Suzuki's swinging bunt landed in infield no-man's land for a single, loading the bases.
No worries, the next batter was Zimmermann. The Nationals' starting pitcher couldn't help himself out, bouncing into a 6-4 fielder's choice to end the threat.
The Tigers threatened again in the third, this time converting with two down. The converter was the best hitter in the game.
After Sanchez (UGH) and Austin Jackson struck out, Hunter doubled over the third base bag. He easily scored on Cabrera's RBI single to left, the Tigers taking a 1-0 lead. (MLB.com video)
Another reason to hate playing in the National League (other than no DH, endless pitching changes and overrated managerial strategy) is the Tigers had to face Span. He showed why Tigers fans despised him as a Twin when he led off the bottom of the third by tripling into to the right field corner. It looked as if there might be a play, Span stumbled rounding second, but the relay was off line. Of course it was off line. It was Span on the bases.
Span would score on Harper's sacrifice fly, tying the game at 1-all.
The Nationals would take the lead when the one Tiger you would expect to play fundamental baseball, didn't.
Leading off, LaRoche singled, Espinosa did the same after one out. Runners on first and second, Suzuki sent a fly to medium right field, LaRoche tagging up. Forgetting the next batter was the pitcher and not bothering to split the base runners, Hunter airmailed the cutoff man trying to nail LaRoche at third. The throw hit LaRoche's hand, Sanchez unable to keep the ball from bouncing into the camera well.
Both runners were given an extra base, LaRoche scoring on the play. Hunter was credited with an E-9 on the throw, the run unearned.
Of course, Sanchez would strike out Zimmermann to end the inning, but the Tigers were now down 2-1.
Bottom of the fifth, one swing of Harper's powerful bat made it a 3-1 game. First pitch swinging with two out, Harper smoked a Sanchez breaking ball deep into the right field seats for his tenth home run of the season.
The Tigers scratched together a two out threat in the sixth on singles by Andy Dirks and Peralta. It would end there, Alex Avila looking at a called third strike on an 0-2 pitch. It was not one of Avila's better at bats.
Sanchez struck out the side in the bottom of the sixth. At 98 pitches, he still had another inning or two in him ... if he were pitching at Comerica Park. This being the NL and the Tigers in need of offense, it was assured Sanchez was going to be lifted for a pinch hitter in the next half inning.
And he was.
I soooo love NL style baseball...
One down in the seventh, the Tigers pinch hit for Sanchez, Jim Leyland calling on ... Don Kelly? Yes, Donnie Baseball over Victor Martinez.
Kelly popped up a 1-2 pitch to short for the second out. Jackson singled, but Hunter popped up, inning over.
Jose Ortega took over for Sanchez in the bottom of the seventh. The rookie's impressive string of appearances continued, retiring the Nationals in order.
Zimmermann having crossed the 100 pitch mark (101) and with a season high of 107, Davey Johnson pulled the extremely effective starter for right-handed reliever Tyler Clippard.
Clippard set down Cabrera and Fielder, but proceeded to get himself in trouble by walking both Dirks and Peralta. But once again, in the exact same situation as in the sixth, Avila struck out with runners in scoring in position.
Joaquin Benoit got the ball for the Tigers in the eighth. The Tigers' setup man tossed a 1-2-3 inning, but somehow needed 25 pitches to do so.
Regardless, the bullpen had kept the Tigers in the game, having set down six straight (including the final two innings from Sanchez, ten consecutive Nationals had taken a seat).
It was up to the Tigers' offense, They would have to score against the closer they weren't interested in signing as a free agent, Rafael Soriano.
Infante hit a sinking liner to left. Defensive replacement Roger Bernadina wasn't sure how to play it, so he dove, making the catch. Martinez pinch hit for Benoit, lining out to Bernadina. Jackson's can of corn to right ended the game.
An absolutely meh game over. Your final score is Nationals 3, Tigers 1.
The first place Tigers drop to 19-12 on the season, their winning streak over at four games. They still hold a 1 1/2 game lead over the Royals in the AL Central,
The 18-15 Nationals remain two games back of the Braves in the NL East. Their winning streak is now at three games.
The finale of the short two game series is Thursday afternoon, to make up for Tuesday's postponement. Doug Fister (4-0, 2.48 ERA) gets the start for the Tigers, Dan Haren (3-3, 5.01 ERA) takes the mound for the Nationals. First pitch is 4:05 PM.