Rookie moves to No. 3, drives in winning run against Diamondbacks

It took Bryce Harper four games to ascend to the No. 3 slot in the order of the Washington Nationals. He justified his promotion with the game-winning hit Wednesday night.

Taking one of the best pitchers in the National League, Ian Kennedy, to the opposite field, Harper ripped a double to the left-field corner to score Ian Desmond from third base in the Nats' 2-1 victory over the Arizona Diamondbacks.

"That change-up is pretty good, so I was trying to wait back on something. I got something to drive," Harper said. "I want to come up as clutch as I can. I love those situations."

The hit in the sixth inning helped deliver Nats left-hander Ross Detwiler (3-1) a win with some relief help from Ryan Mattheus, Tyler Clippard and Henry Rodriguez (sixth save). The trio of right-handers set down the final eight hitters they faced.

In beating the Diamondbacks twice in three games, the Nationals (16-9) solidified their hold on first place in the National League East and captured their seventh series in eight tries.

It was a night of clutch hitting and stingy pitching as the Nationals seem to have regained the formula they used en route to a 14-4 start before a five-game losing skid. The Nats got just four hits, but three were timely enough.

The Nats went up 1-0 in the second as Jayson Werth doubled down the third-base line, moved to third on a balk by Kennedy (3-1) and scored on a groundout by Rick Ankiel.

The winning run was set up in the sixth when Desmond led off with a hard-hit double into the corner. Two batters later, Harper hit a ball to the same spot for his fourth double in five major league games.

The rest was about Detwiler as he provided Washington's 19th quality start, tied for second best in the major leagues.

A successful call-up last season, when he pitched to an ERA of 3.00 in 10 starts and five relief appearances, should have guaranteed the left-hander a spot in the rotation, especially considering the investment the team made in him as the No. 6 overall pick in the 2007 draft.

But this spring Detwiler found himself slated for long relief -- or perhaps even a trip back down to Triple-A Syracuse. Those plans changed, however, when Chien-Ming Wang stepped awkwardly on first base in spring training, blew out a hamstring and created an opening in the rotation.

"If I'm in the 'pen and Wang doesn't get hurt, then I've got to do whatever I can," Detwiler said. "I can't dwell on it and say, 'Woe is me.' That's not gonna get me anywhere. That will get me no job at all."

With Detwiler pitching to an ERA of 1.59 and a WHIP of 0.99, consider it likely that he will hold on to his slot for a while.

The 26-year-old held Arizona (13-13) hitless through the first four innings. He allowed three hits and three walks in 61?3 innings.

Arizona's lone run came in the sixth on a one-out walk by Willie Bloomquist and a double to right-center by Aaron Hill that just eluded the glove of a diving Werth near the warning track.

Werth caught everything else hit his way, including the final out of the game, his 10th putout of the night.