Game 25: Nationals 2, Diamondbacks 1

Davey Johnson’s instincts and Bryce Harper’s hustle could be just what the Nationals need to get over the hump this season.

Johnson’s decision to put Harper third in the batting order paid immediate dividends, as the rookie doubled in the go-ahead run in the sixth inning of the Nats’ 2-1 win over the  Arizona Diamondbacks.

The Nats took two of three from Arizona to give them victories in seven of the eight series they’ve played so far this season and kept them atop the National League East at 16-9, a game and a half ahead of Atlanta.

Ross Detwiler (W, 3-1) allowed one run on three hits and three walks, striking out two, over 6.1 innings. Ian Kennedy (L, 3-1), allowed four hits and a walk with four strikeouts over seven innings for the Diamondbacks. Henry Rodriguez (S, 6) worked a scoreless ninth for the save.

With one out in the sixth, Harper laced an 0-1 fastball deep into the left field corner to score Ian Desmond, who had doubled to lead off the inning. It would have been his second time on base for the game if not for a rookie mistake in the first inning. Harper appeared to beat out a slow roller to Kennedy and took second when Kennedy overthrew first baseman Paul Goldschmidt. But Harper missed the bag while rounding first and trying to avoid Goldshmidt, and was called out on appeal.

The Nats manufactured a run with the help of a pitching miscue in the second inning for a 1-0 lead. Jayson Werth led off with a double. After Chad Tracy walked and Danny Espinosa struck out, Kennedy balked with Rick Ankiel at the plate, advancing the runners. Werth scored on Ankiel’s ground out to first.

Arizona tied it in the top of the sixth when Aaron Hill doubled to right, scoring Willie Bloomquist, who had walked with one out.

After the Nats took the lead in the bottom of the inning, the Diamondbacks put the tie run on second when Goldschmidt singled and took second on Miguel Montero’s groundout to second base. Ryan Mattheus relieved Detwiler and retired Ryan Roberts and A.J. Pollock to end the inning.

Champ of the Game: Harper. Except for the baserunning blunder, the kid can seem to do no wrong so far. He’s a doubles machine.

For the Diamondbacks, it was Kennedy, whose biggest mistake was the balk that put Werth in scoring position.

Chump of the Game: Espinosa continued to struggle for the Nationals. He went 0-for-3 and stranded two runners. At this pace, he will play his way out of the lineup when Ryan Zimmerman returns.

For Arizona, Pollock was 0-for-3 and left two men on base, lowering his average to .120.

Unsung Hero: Detwiler, who continued his run as perhaps the best No. 5 starter in baseball with his longest outing of the year, lowering his ERA to 1.59.

For the Diamondbacks: Hill had the only RBI of the game.

Next Game: May 4, 7 p.m., vs. Philadelphia at Nationals Park. Kyle Kendrick (0-2, 6.59) vs. Stephen Strasburg (2-0, 1.13).