Having defeated the New York Mets in five of six matchups this season, the Washington Nationals look to continue their success against their NL East rival when the teams begin a three-game set in the nation's capital on Tuesday.The Nationals have averaged nearly six runs per game against the Mets this season, although the teams have not met since mid-May. Washington's Gio Gonzalez and New York's Zack Wheeler will square off Tuesday in a matchup of pitchers who sit below .500 despite sub-4.00 ERAs.The Mets lost three of four against the San Francisco Giants in their most recent series, including a 4-3 setback on Monday afternoon. Daniel Murphy was the offensive bright spot for New York, drilling a two-run homer among his two hits, marking the sixth time in nine games that he has recorded at least two hits. The Nationals were topped by the Baltimore Orioles 7-3 on Monday in a one-game makeup despite a home run from Wilson Ramos.TV: 7:05 p.m. ET, SNY (New York), MASN2 (Washington)PITCHING MATCHUP: Mets RH Zack Wheeler (6-8, 3.60 ERA) vs. Nationals LH Gio Gonzalez (6-7, 3.88)Wheeler has worked at least six innings while giving up two runs or fewer in each of his last six starts. He gave up two runs in 6 2/3 frames in Wednesday's win over Philadelphia, although he did allow a home run for the third straight outing. Wheeler has faced the Nationals twice this season, going 0-2 with a 6.00 ERA.Gonzalez has no wins to show for his last four outings and has failed to escape the fourth inning in two of his last three starts. He was charged with five runs and eight hits in 3 2/3 frames against Philadelphia his last time out and struck out only two batters - two shy of his previous season low. Veteran outfielder Curtis Granderson is 2-for-19 against Gonzalez with seven strikeouts.WALK-OFFS1. Mets C Travis d'Arnaud is 1-for-18 over his last six games.2. Gonzalez is 6-2 with a 3.10 ERA and a .195 opponents batting average lifetime against New York. 3. Washington OF Denard Span has reached base via a hit or a walk in 30 straight games.PREDICTION: Nationals 4, Mets 2