They will look to keep it going on Tuesday, while the Blue Jays (31-30) look to cool them down and stay above .500.
Nationals manager Davey Johnson, when asked on Monday about the Blue Jays, said they are similar to his club.
"They've got good starting pitching, they swing for the fences a lot, [we've] got to stay away from their hot zones, but we match up pretty good against them," Johnson said.
Tuesday's tilt consists of two pitchers with more losses than wins in Washington's Chien-Ming Wang (1-2, 5.11 ERA) and Toronto's Henderson Alvarez (3-5, 3.76).
In his last start on Thursday, a 3-1 loss to the Mets, Wang allowed just two runs on eight hits over 5 1/3 innings, walking three and striking out one. He got out of bases-loaded jams in the second and third innings of that game.
After the game, which marked the last time the Nationals lost, Johnson said Wang was having problems with his arm slot.
"I liked his arm strength and everything," Johnson said. "He's having a little problem, he gets to the side of the ball. He doesn't stay on top of it. Sometimes he gets out of the slot that he needs to be in. When he stays in that slot, his stuff is outstanding. It's just a consistency thing with him."
Alvarez, the 22-year-old from Venezuela, is seeking his first win since May 10. In Thursday's 4-3 loss to the White Sox, his last start, he gave up three runs on seven hits in seven innings, at one point retiring 12 straight batters. He was handed a no-decision.
"I'm happy with the way I pitched," he said after the game through interpreter Luis Rivera. "I feel like all my pitches were working tonight, the sinker, the slider and the changeup. I was happy with that outing."
Nationals: Storen throws off mound for second time
Closer Drew Storen threw off a mound on Monday for the second time in four days, and Johnson said there were no problems afterward. Storen has not played this season after undegoing surgery in April to remove bone chips from his right elbow.
It's possible Storen, who the Nationals drafted 10th overall in the 2009 Draft, could return around the All-Star break in July. The 24-year-old saved 43 games last season, posting an ERA of 2.75.
"I think he was a little disappointed because he thought he threw a little bit better than he felt. ... But I wouldn't expect anything less," Johnson said on Monday. "Every time he throws the ball, he wants to throw it through the wall. But he had no problems throwing, so he is right on track."
Center fielder Roger Bernadina left in the fourth inning of Monday's game with a strained right hamstring.
Blue Jays: Morrow leaves Monday's start with oblique injury
Starting pitcher Brandon Morrow left in the first inning of Monday's game after throwing just nine pitches with a left oblique strain.
Losing Morrow for any extended period of time would be a blow to the Blue Jays, as he has been their best pitcher in 2012. Entering Monday's start, Morrow was 7-3 with a 2.90 ERA in 12 starts with 67 strikeouts to just 24 walks. He leads the Major Leagues with three shutouts.
Chad Beck took over for Morrow on Monday and surrendered three runs (two earned) in 3 2/3 innings.
Center fielder Colby Rasmus, who had just three home runs in his first 45 games of 2012, has hit six long balls in his last 15 contests. He hit his second homer in as many days with a first-inning blast in Monday's loss.
Washington is a season-best 13 games over .500 for the first time since July 2005, when it was 54-41 through 95 games.
Toronto announced on Monday the signings of 22 of their 44 recent Draftees, including first-round pick D.J. Davis, an outfielder.
Wang is 4-2 with a 4.82 ERA in 10 career starts against the Blue Jays. Alvarez has never faced the Nationals.