NEW YORK -- The Mets may have not been perfect throughout their recent vault up the National League Wild Card standings, but neither has anyone else. So while the Mets have waded through a pile of mounting injuries, they've kept one eye on the out-of-town scoreboard, where the Cardinals, Pirates and Marlins have all also scuffled to varying degrees.
It has provided a prime opportunity for the Mets, who continued taking advantage on Saturday with a 3-1 win over the Nationals at Citi Field. Rotation fill-in Robert Gsellman submitted six strong innings, Curtis Granderson drove home two runs and the Mets bent but did not break against Washington's offense, which stranded nine runners on base.
"Tonight was a big game for us to have," Mets manager Terry Collins said. "We weren't supposed to win it. We had a rookie pitching. We have a rookie pitching tomorrow night. But that's why it's a great game -- you just never know."
The Mets took the lead for good in the third inning, on Granderson's two-run single off Nationals starter Tanner Roark. That was all Roark allowed, but it was enough; the Mets tacked on a third run on James Loney's RBI double off Matt Belisle in the sixth.

Though the Nationals filled the basepaths all evening, their only run came on Anthony Rendon's sacrifice fly in the first. Gsellman scattered six hits, three walks and an error in six innings, and four Mets relievers did the rest. It hardly mattered that four Nationals hitters reached base multiple times -- including Bryce Harper, who singled once and walked twice, but never scored.
"We had a few opportunities. We hit a couple of balls hard. [The Mets] had some opportunities, too," Nationals manager Dusty Baker said. "That was a big hit Granderson got."
Combined with the Cardinals' loss in Cincinnati, the win moved the Mets within one game of a Wild Card spot. The Nationals still hold a comfortable 9 1/2-game division lead with 27 to play.
MOMENTS THAT MATTERED
Driving in a pair: Going into the game with a .116 average with runners in scoring position -- the league's worst single-season mark since Melvin Upton Jr. batted .108 with RISP in 2013 -- Granderson came through with a two-run single off Roark in the third. The hit gave Granderson 40 RBIs to go along with his 22 home runs.
"I do believe in him," Collins said of Granderson. "I do believe he comes up with big hits. Tonight he did."
No depth from Roark: Roark usually goes seven innings, but not this time, as he pitched five, allowing two runs on five hits. His toughest inning was the third, when he gave up the two-run single to Granderson.
• Burnett pitches in Majors for 1st time since '14
"I wasn't pitching in the strike zone effectively," Roark said. "It was not a good outing in my mind. I was not getting ahead, is the main thing."

Cutting through the heart of the order: Tensions heightened in the seventh inning, when Jayson Werth singled with one out to bring Daniel Murphy to the plate in a two-run game. In came rookie left-hander Josh Smoker, who served up a sharp line drive to center, but Michael Conforto made a diving play to snare it. Smoker then struck out Harper on four pitches, the last of them a slider in the dirt that had Harper flailing.
• Unlikely heroes stepping up for Mets

"That's a tough situation right there," Conforto said. "If that ball gets past me, Werth probably scores from first. But with the jump that I had and the way the ball was carrying -- Murph hit that ball really hard -- I felt like I had an opportunity to go down and get it. It definitely felt good to get that one and keep Murph off the bases."

Leaving 'em stranded: The Nationals went 0-for-7 with runners in scoring position. Their biggest chance to score came in the sixth inning, when they had runners on first and second with no outs. After Ryan Zimmerman grounded out to advance the runners one base, Danny Espinosa struck out swinging and pinch-hitter Ben Revere grounded out to end the threat.

QUOTABLE
"It means a lot. It's definitely fun baseball to be a part of. Hopefully, we can pull it out." -- Gsellman, on his role in the Mets' playoff chase
SOUND SMART WITH YOUR FRIENDS
With a single in the first inning, Murphy extended his hitting streak against the Mets to all 15 games he's played against them this season. That matches Tony Gwynn for the longest streak against the Mets to start a career with a team.
UPON FURTHER REVIEW
After Loney's double in the sixth inning, Oliver Pérez entered in relief and grazed Kelly Johnson's hand with his first pitch. Baker challenged the play, but the call stood.

WHAT'S NEXT
Nationals: On Saturday afternoon, Baker had a change of heart about who will pitch on Sunday night at Citi Field, so instead of right-hander Max Scherzer getting the nod against the Mets, right-hander Reynaldo López will take the mound at 8:08 p.m. ET and face New York for the first time in his career.
Mets: A pleasant surprise for a pitching-starved team, Seth Lugo will take the mound for the 8:08 p.m. ET series finale against the Nationals. Since joining the rotation in place of Steven Matz, Lugo is 2-1 with a 2.55 ERA, holding opposing hitters to a .226 average.
Watch every out-of-market regular-season game live on MLB.TV.