ST. LOUIS -- From the first pitch of Sunday's game, Max Scherzer knew it was back.

He knew he could put his fastball at the knees any time he wanted. He knew his fastball had the movement it needed. He knew his secondary pitches were working in concert.

And as it turned out, everyone soon figured out Scherzer's old hometown team didn't have much of a chance to hit him.

Winning for the first time in three starts back in his native St. Louis, Scherzer powered his way through seven scoreless innings as the Washington Nationals polished off a sweep of the Cardinals with a 6-1 decision at Busch Stadium.

Scherzer (3-1) allowed just four hits and never let a runner reach scoring position, walking none and whiffing nine. The result gave Scherzer victories against every major league team but Detroit, the team he left following the 2014 season to sign with Washington.

"I made a little mechanical change and I instantly felt like I was on top of the ball," Scherzer said. "When I can throw a fastball early in the count and get ahead, it sets up all of my stuff. That's why I felt I was successful today."

It was the first time the Nationals (17-7) swept the Cardinals (12-13) in a series in St. Louis since moving from Montreal after the 2004 season. They did it in decisive fashion as well, outscoring the Cardinals 17-6 and recording at least 10 strikeouts in every game.

First-year manager Dusty Baker, who skippered a lot of Cincinnati teams to a lot of losses over the year in St. Louis, could be excused for marveling at his team's weekend.

"I can't ever remember coming in here and sweeping the Cardinals," he said. "They're a tough bunch, especially here."

Baker said St. Louis might have been affected by a punishing travel schedule which saw it get home after 4 a.m. Friday following the series finale in Arizona Thursday night, then play a day game Saturday after Friday night's 5-4 loss.

But the series sweep continued an early-season trend for the Cardinals, who are 1-8 against winning teams (Pittsburgh, Chicago Cubs, Washington) and have been outscored in those games 42-19.

The only win in those games was delivered by Carlos Martinez, and he matched Scherzer pitch-for-pitch through five innings, retiring 15 of the first 16 hitters he faced. But Martinez cracked a bit in the sixth when he permitted an RBI single to Matt den Dekker.

Martinez was knocked out in the seventh, undone by back-to-back homers. Clint Robinson ambushed a first-pitch fastball with Jayson Werth aboard, sending it 419 feet to the right-center field seats, and Danny Espinosa followed on the next pitch with a 420-foot blast just to the left of Robinson's shot.

Martinez departed two batters later after Scherzer's second hit of the day, finishing with seven hits and four runs over 6 2/3 innings with no walks and eight strikeouts as he fell to 4-1.

But the huge crowd around Martinez's locker after the game wasn't totally interested in his views on the game. He is the defendant in a civil lawsuit filed by Diana Molina in Florida on April 21 -- alleging assault, libel and slander -- for more than $1.5 million.

Martinez politely danced around the issue when queried about it.

"The only thing I can control is to come here and help my team to win," Martinez said through an interpreter. "That's my main focus. I have nothing more to say about it."

The Nationals added runs in the eighth on Daniel Murphy's RBI double and in the ninth when Chris Heisey belted a two-out pinch-homer to left-center.

St. Louis avoided a shutout when Brandon Moss cracked a two-out solo homer in the ninth, but it wasn't nearly enough to spoil a successful homecoming for Scherzer and a historic weekend for Washington.

"Getting a sweep is big for our ball club," Scherzer said. "Everyone had a hand in it today."

NOTES: St. Louis C Brayan Pena (left knee) has been working out on an antigravity treadmill, but is still at least two weeks away from making more strides in rehab. Pena was injured late in spring training. ... Washington RHP Joe Ross had a scoreless inning streak of 20 1/3 innings stopped in the fifth inning Saturday, which was the National League's second-longest streak in April. ... Cardinals SS Jhonny Peralta (left thumb) took grounders Sunday as well as controlled swings. Peralta is said to be about three weeks away from starting a rehab assignment.