Knuckleballer R.A. Dickey comes back off a loss for just the fourth time this season tonight when the New York Mets host the Colorado Rockies in the first of four games at Citi Field.

The 37-year-old Tennessee native has won 15 of 19 decisions in 2012, but was beaten, 6-1, by the Cincinnati Reds in his most recent outing on Aug. 15 after allowing 10 hits and five runs in six innings.

He's unbeaten in three previous starts coming off losses, combining to allow 12 hits and three runs in 23 innings.

A seven-time winner in eight decisions across 12 home appearances in 2012, Dickey has held opponents to a .203 batting average in New York while striking out 81 batters in 81 1/3 innings.

He dropped his lone career decision against Colorado.

The Rockies start righty Alex White, who turns 24 at the end of the month and faces the Mets for the first time in his 25th big-league start.

He debuted with Colorado by making three starts in 2010 and made seven more last season before becoming a more regular fixture in the rotation across 14 starts in 2012.

He's allowed 80 hits and 47 runs in 69 innings this season and is without a win since June 3, when he topped the Los Angeles Dodgers, 3-2, with 6 2/3 innings of two-hit ball.

In eight starts since, he's 0-3 and has pitched more than five innings just twice.

On Sunday in Colorado, Jordan Pacheco slugged a go-ahead two-run home run in the fourth and the Rockies salvaged a four-game split against the Miami Marlins with a 3-2 win.

Dexter Fowler picked up a pair of hits and drove in a run for the Rockies, who snapped a two-game skid.

Drew Pomeranz gave up two runs - one earned - to register a no-decision before Adam Ottavino (5-1) tossed three scoreless frames in relief.

"We had to pitch well from the fifth inning on and we did," Colorado manager Jim Tracy said.

In Washington, Danny Espinosa hit a two-run homer while Bryce Harper homered and hit an RBI triple, as the Nationals took the rubber match of a three-game series against the Mets with a 5-2 victory.

Kelly Shoppach went 2-for-3 with a walk and an RBI for the Mets, whose starter, Jeremy Hefner (2-5), yielded five runs on eight hits over five innings.

New York went 2-for-21 with runners in scoring position in the series, including a 1-for-11 effort on Sunday that saw 10 runners stranded.

The Mets won two of three games from the Rockies in April in Denver, while the Rockies won five of seven between the teams in 2011.