Cy Young Award contender Jacob deGrom and the Mets downed the Nationals 4-2 Friday night and about an hour later the Atlanta Braves (86-68) defeated the Phillies, officially eliminating the Nationals from the NL East title race.
The two-time defending division champion, Washington (77-77) enters Saturday eight games behind in the race for the second NL wild-card spot with eight games remaining.
Friday night the Nationals dropped their second straight to the Mets (72-82) as deGrom burnished his Cy Young Award credentials. He allowed one run on three hits over seven innings, turning his 23rd consecutive quality start -- a major league record -- and improving to 9-9 with a 1.77 ERA.
"He's just able to do things other guys aren't," Mets right fielder Jay Bruce said afterward. "He goes out there and it's been pretty automatic. He's either going to give up zero or one pretty much every time he goes out there."
Washington got a run off deGrom in the second, but he settled in, retiring the final seven batters he faced and 13 of the last 14.
The Nationals got a run in the ninth and had the tying run at the plate twice, but Juan Soto struck out and Ryan Zimmerman flied out.
"The talk in the clubhouse, as you see it again tonight, is they want to win every game," Nationals manager Dave Martinez told MASN.com. "We had the tying run up. So, they're not going to quit. I know they're going to finish this out."
The Mets got three hits and a walk from catcher Devin Mesoraco, who hadn't played since Sept. 3 due to a neck injury.
New York leads the season series 10-7 with two games remaining.
New York right-hander Corey Oswalt (3-2, 6.31 ERA) opposes right-hander Austin Voth (0-1, 11.81) in a 4:05 ET start Saturday.
Oswalt is starting in place of Zack Wheeler, who was shut down after a dominant second half as he was close to pitching 100 more innings this season than a year ago.
Last time out, Oswalt allowed one unearned run on three hits in 2 2/3 innings at Fenway Park. He took a no decision in the Mets' 5-3 loss.
Oswalt has pitched against the Nationals twice. He worked five innings and allowed one run on two hits in a no decision July 15 at Citi Field, and he gave up six runs in one inning of relief versus Washington on Aug. 26.
Voth is stepping in for Tanner Roark, who is with his family after his wife had a baby this week. Voth, a rookie, is making his second career start and second against the Mets. On July 14 he allowed seven runs on nine hits over 4 1/3 innings versus New York and took the loss in a 7-4 defeat.
With outfielder Adam Eaton suffering some stiffness in his knee, Victor Robles is getting some extra playing time in center.
"You get some consistent at-bats in a row," Martinez told MASN.com. "You just get to watch him play baseball all around. ... Watch him play defense, watch him move around and run the bases. He's a good athlete. It's nice to see him go out there and play a few days in a row and see what he can do."
He went 1-for-4 against deGrom but cost the Nationals an early run when he took a bad route on Amed Rosario's leadoff double.