"That one pitch didn't do much -- out and over the plate, and Davis crushed it," Nationals manager Davey Johnson said.
"He was nasty tonight," Davis said about Jackson. "He had everything, he was throwing all of his pitches for strikes. His fastball was moving everywhere, and the slider was real sharp tonight."
The home run by Davis was enough for New York against Jackson [7-8], who struck out a season-high 11 batters and allowed just two hits during his seven innings.
"At the end of the day, the results were not what we wanted," Jackson said. "[My stat line] pretty much doesn't matter. It's good to come out and pitch well, but at the end of the day, the objective is to win the game."
Johnson felt Jackson pitched one of his best games of the season.
"Jackson has been good all year. It was probably the most dominant I have seen him pitch," Johnson said "He had outstanding stuff. His fastball was dropping off the table and had a lot of life and moving. ... I don't know how many K's he had, but he had a lot. His stuff was so electric. He was overmatching them."
Mets left-hander Jonathon Niese pitched 7 1/3 scoreless innings and allowed just five hits. The Nationals had runners in scoring position three times during the game. Their best chance came in the first inning.
Washington had runners on first and second with one out, but Michael Morse flied out to Mike Baxter in right field, and Adam LaRoche grounded out to second baseman Daniel Murphy.
"You have to tip your hat to Niese. He really had a big sweeping cutter that he was using," Johnson said. "The guys had a hard time centering on it. He pitch one heck of a ballgame."
Mets relievers have been struggling this year, and the way the Nationals have been scoring runs in the late innings, one had to feel that the Nationals would come back and win the game. But the New York bullpen was perfect after Niese left the game.
Jon Rauch retired the two hitters he faced in the eighth, and Frank Francisco retired the side in order in the ninth for his 20th save.
Ryan Zimmerman led off the ninth inning and hit a long fly ball in right-field corner. Baxter tracked it down and made a nice catch near the line. Zimmerman was surprised Baxter was playing no-doubles defense with a two-run lead.
"I had no idea where he was playing and why he was playing there," Zimmerman said. "It's 2-0, and I don't know why you would play no doubles. It was a good catch, but I really don't know why he was there. But he got me out, and it worked."
"Their bullpen and their closer, especially, have had their problems. A little bit of momentum there could have really helped," Johnson said.
The Nationals didn't lose any ground in the National League East standings with the loss, holding their four-game lead over the Braves, who lost to the Dodgers, 6-1, on Saturday.