New York @ Washington preview

Last Meeting ( Jun 30, 2013 ) Washington 13, NY Mets 2

Bryce Harper was tagged with the "phenom" label by the time he was 16, but the Washington Nationals' center fielder played the role of savior on Thursday in helping his team snap a six-game losing streak. After the Nationals squandered a four-run lead in the top of the ninth versus Pittsburgh, Harper's first career walk-off homer gave Washington a much-needed victory and some momentum heading into a four-game series with the visiting New York Mets.

"We really needed it," Harper said. "Hopefully this one will carry on into (Friday) and the next day." Washington trails NL East leader Atlanta by eight games and is two ahead of the Mets, who are coming off a four-game split with the Braves. New York is tied with the Nationals in the loss column entering Friday's doubleheader, but plays considerably better on the road (24-23) and has its own phenom, Matt Harvey, set to start Game 2.

TV: 1:35 p.m. ET, SNY (New York), MASN (Washington)

PITCHING MATCHUP: Mets RH Jenrry Mejía (2012: 1-2, 5.63 ERA) vs. Nationals RH Jordan Zimmermann (12-5, 3.01)

Mejía will be making his first start of the year, having been on the disabled list since March with inflammation in his elbow. The 23-year-old Dominican was once considered an off-the-charts prospect, regarded in the same light as Harvey and fellow right-hander Zack Wheeler before undergoing Tommy John surgery in 2011. Mejia is 2-0 with a 0.82 ERA in two outings at Double-A Binghamton.

Zimmermann is coming off a rare clunker, lasting a career-low two innings and getting battered for seven runs by the Los Angeles Dodgers on Sunday. It was the second straight loss for Zimmermann, who was 4-0 in his previous seven outings, including an eight-inning stint when he limited the Mets to four hits and two unearned runs. Zimmermann is 3-3 with a 2.71 ERA in 13 career starts versus New York.

WALK-OFFS

1. Zimmermann is 9-1 with a 2.50 ERA in 12 home starts this year.

2. The Nationals and Mets have split eight meetings this season.

3. New York is playing its third straight four-game series, the first time that's happened since August 2000.

PREDICTION: Nationals 5, Mets 2.