The Washington Nationals are close to matching their longest win streak in franchise history. They can move a step closer by tying their longest on the road.

The Nationals will seek that ninth straight victory away from home - and their ninth in a row overall - during Sunday's series finale against the Arizona Diamondbacks.

Washington (71-43) is closing on its first division title in franchise history on the strength of its major league-best 39-21 road record. The Nationals' success there has helped put them 4 1/2 games ahead of Atlanta in the NL East.

After falling behind by three runs early Saturday, they found a way to keep things going by rallying for a 6-5 victory. Ryan Zimmerman singled in a pair of runs in a five-run fifth, and Jesus Flores drove in what proved to be the go-ahead score with another single.

"We were able to get a win. It wasn't necessarily the way that I planned for it to go, but somehow it worked," pitcher Edwin Jackson said.

Washington has outscored its last eight overall opponents 46-23 and its last eight road opponents 47-26.

"I really like our offense. I like the way everybody's approaching the at-bats," manager Davey Johnson told the team's website. "It's a lot of fun for me."

That win put the Nationals within two of matching a franchise-best 10-game streak, accomplished four times and most recently June 2-12, 2005. To get a crack at that milestone, Washington must first tie its nine-game road win streaks set July 29-Aug. 10, 1994, and equaled Sept. 12-26, 2011, on Sunday.

Ross Detwiler (6-4, 2.99 ERA) will try to lead his team to that victory while continuing his recent success against the Diamondbacks (57-57), losers in six of eight. The left-hander is 2-0 with a 1.38 ERA over his last two matchups, including a 2-1 win May 3.

Detwiler allowed one run and three hits over 6 1-3 innings in that game but gave up a career-high seven runs - four earned - during his only outing at Chase Field on Aug. 5, 2010.

He has allowed a combined two runs and six hits over his last 14 innings but might have to outduel fellow left-hander Patrick Corbin (3-4, 3.53).

Corbin is 1-0 with a 1.50 ERA in his two starts since being called up from Triple-A Reno on Aug. 1. After pitching six scoreless innings against the Los Angeles Dodgers, the rookie fanned a season-high seven and gave up two runs over six innings Tuesday during Arizona's 10-4 win in Pittsburgh.

Corbin was 2-3 with a 5.27 ERA during his first five major league starts before being sent back to the minors May 22. He pitched exclusively in relief following another call-up June 27.

With Corbin's help, the Diamondbacks will try to avoid their first home sweep to the Nationals since May 14-16, 2004, when that franchise was playing its final season as the Montreal Expos.

Washington recorded its most recent sweep in the all-time series from Aug. 7-9, 2009.