By NICOLINO DIBENEDETTO
(AP) -- The Washington Nationals are doing their best to turn the NL East into a two-team race, and Gio Gonzalez deserves a good share of credit.
R.A. Dickey, meanwhile, is trying to keep the New York Mets in contention.
The NL's co-leaders in wins will start opposite each other Thursday when the Nationals try to sweep a three-game series from the Mets, who are looking to avoid their longest losing streak in more than a year.
Washington (53-36) is trying to widen the 4 1/2-game gap on second-place Atlanta in the East standings before hosting the Braves for a four-game set starting Friday.
The Nationals - who won 5-4 on Tuesday and 4-3 on Wednesday - also have a chance to drop New York (46-45) further back by sweeping the Mets at home for the first time since Sept. 28-30, 2009.
The Mets were 2 1/2 games behind Washington at the end of June, but losing nine of 12 - including their current six-game skid - has moved them eight games off the pace.
New York last dropped seven straight April 10-16, 2011.
"There are no saviors. Just continue to battle and battle, get out of this and go win six in a row," Mets manager Terry Collins said. "That's the only way you can play. We have a great clubhouse. Watch each other's backs and continue to move forward."
Facing Gonzalez (12-4, 2.90 ERA) in the nation's capital may not be the easiest way forward.
The left-hander was sharp again Saturday, but could have used some help from the offense in a 2-1 loss at Miami. He didn't get a decision after collecting nine strikeouts and allowing two runs in six innings.
"He pitched a jewel in his hometown," manager Davey Johnson said.
Gonzalez is tied with Dickey (12-1, 2.64) for the most wins in the league. They were teammates in last week's All-Star game, throwing an inning each to help the NL to an 8-0 victory.
They started opposite each other in Gonzalez's only previous meeting with the Mets, a pitchers' duel on June 22, 2011. Gonzalez, then with Oakland, allowed one run and four hits with eight strikeouts in seven innings, while Dickey struck out nine in eight frames, yielding one run and three hits.
The Mets won that contest 3-2 in 13 innings.
New York could use another dominant outing from its knuckleballer, who is 3-1 with a 2.40 ERA in seven starts at Washington, winning his last two while allowing three runs in 13 1-3 innings. He struck out eight in 7 1-3 scoreless innings of a 3-1 victory June 7.
"I'm sure R.A.'s going to give us a good game because that's what's going to crack this thing," Collins said. "This game, as you can see by what they do, is on the mound. If we continue to pitch, we'll win our games."
Dickey has struggled lately, though, surrendering 10 runs and 19 hits over his last two starts spanning 12 innings. However, he didn't get a decision in either of those contests, so his 10-game winning streak is still intact.
"Every season has a storm or two in it," Dickey said. "You just kind of have to stay afloat. It'll turn."
Washington's Bryce Harper is 0 for 3 with two strikeouts against Dickey, but he's batting .382 in his last eight home games.
Updated July 19, 2012