KANSAS CITY, Mo. -- His best pitch of the night looked so good, Jordan Zimmermann wanted to see it again.

So the husky right-hander went straight to the replay machine in the Washington Nationals' clubhouse.

He watched once again as Kansas City's Eric Hosmer flailed hopelessly at a wicked slider, striking out in the first inning and setting the tone for a 7-2 victory over the Royals on Saturday night.

"I just watched it on replay. It started off as a ball. It really went off the plate. I'm not real sure why he swung at it, but it almost hit him in the back foot," said Zimmermann (15-7), who tied St. Louis' Adam Wainwright for the NL lead in wins. "I threw a lot of good sliders tonight."

Rebounding from one of his worst career outings, Zimmermann went 7 2/3 innings, allowing two runs and eight hits.

He struck out seven and walked just one. After George Kottaras singled with two out in the fourth, Zimmermann retired 11 straight until Emilio Bonifacio walked with one out in the eighth.

"I had four pitches working and when I have that going, it's usually a fun night to be out there," he said. "And the offense got some runs early and allowed me to settle in."

Ian Desmond hit his 18th home run as the Nationals won their fifth in a row, all on the road.

The Nationals have won 11 of 15 overall while the Royals have been staggering.

After a 19-5 surge gave fans hope for an end to a 27-year playoff drought, they've lost seven in a row and 10 of 12.

"It's frustrating," left fielder Alex Gordon said. "I don't like losing streaks and I don't like losing streaks after we've been playing so well. We're professionals. We'll keep playing and grinding."

Wade Davis (6-10) allowed seven runs and eight hits in six innings, including Desmond's two-run home run in the sixth. He walked three and struck out four.

The Nationals, who scored seven runs in the fourth inning of a come-from-behind 11-10 victory on Friday, scored four in the same inning against Davis.

Ryan Zimmerman walked leading off and sped to third on a single by Bryce Harper, who had an RBI single in the first.

Wilson Ramos hit a sacrifice fly, Tyler Moore delivered an RBI double and Chad Tracy brought in two more runs with a bloop single.

"We're putting good at-bats together, seeing the ball well, pitching well, playing good defense," Desmond said. "It's just been a matter of time. We're starting to get hot. Guys are starting to see the ball better."

The Royals bunched three singles off Zimmermann in the third, including Hosmer's run-scoring hit into left-center. All nine of KC's hits were singles.

Fernando Abad relieved Zimmermann with two out and one on in the eighth and allowed an RBI single to Mike Moustakas before striking out David Lough to end the inning with the bases loaded.

With the victory, the Nationals guaranteed a winning interleague record for the third straight season.

Game notes
Washington outfielder Jayson Werth, who hit a two-run home run Friday night, sat out with an infection between the toes of his right foot. He was hoping to play on Sunday. ... In a salute to the Negro leagues, the Royals wore the uniform of the Kansas City Monarchs while the Nationals dressed as the Washington Homestead Grays, a rematch of the 1942 Negro Leagues World Series. ... Alex Gordon recorded his league-leading 11th outfield assist when he threw out Ryan Zimmerman in the first inning trying to stretch a single into a double.