NEW YORK -- Washington right-hander Doug Fister dominated the New York Mets again Sunday when he threw 6 1/3 shutout innings to lead the Nationals to their second straight 1-0 win at Citi Field.

The Nationals (12-14) won three of four from the Mets to close within four games of first-place New York (16-10), which has lost seven of its last 10.

Fister allowed five hits and walked none while striking out three in improving to 5-0 with an 0.82 ERA in five career starts against the Mets. He retired 19 of the final 22 batters he faced following back-to-back singles to open the game by Mets right fielder Curtis Granderson and center fielder Juan Lagares.

Right-hander Tanner Roark got the final two outs of the seventh. Left-hander Matt Thornton walked two in two-thirds of an inning before right-hander Aaron Barrett struck out left fielder Michael Cuddyer to strand two runners in scoring position. Right-hander Drew Storen earned his seventh save with a perfect ninth.

Just as they did Saturday, the Nationals scored their lone run in the first. Center fielder Denard Span drew a leadoff walk and was forced on second on a grounder by third baseman Yunel Escobar, who reached when shortstop Ruben Tejada bobbled the relay throw.

Left fielder Jayson Werth followed by beating out another potential double play grounder. Right fielder Bryce Harper singled and first baseman Ryan Zimmerman followed with a single to score Werth.

Shortstop Ian Desmond finished with two hits.

Right-hander Dillon Gee made a unique bit of team history for the Mets but took the loss after allowing one run on six hits and five walks (one intentional) while striking out five over five-plus innings. It was the 51st straight start in which Gee threw at least five innings, breaking a team record he shared with right-hander Dwight Gooden.

Gee was spared further damage in the fourth, when Cuddyer reached over the fence to rob Zimmerman of a homer, and in the sixth, when left-hander Alex Torres inherited a bases-loaded situation but struck out the next three batters.

Lagares had his third straight two-hit game.

NOTES: Mets SS Wilmer Flores got a second straight day off. Flores has committed four errors in his last five starts and seven overall. He also struck out four times Friday night. Manager Terry Collins said Monday's off-day played into his decision to rest Flores again and provide him some extra time to clear his head. ... The Mets' top prospect, RHP Noah Syndergaard, threw seven shutout innings for Triple-A Las Vegas Saturday. Syndergaard has thrown 14 straight scoreless innings. ... Nationals CF Denard Span returned to the lineup after missing two games with a sore abdomen. ... According to the Elias Sports Bureau, the Nationals' 1-0 win Saturday snapped a streak of 64 straight 1-0 losses on the road. Prior to Saturday, the Nationals hadn't earned a 1-0 road win since beating the Mets at Shea Stadium on May 15, 2008.