Buddy Carlyle #43 of the New York Mets celebrates with...

Buddy Carlyle #43 of the New York Mets celebrates with teammate Wilmer Flores #4 after notching a save against the Washington Nationals on Opening Day at Nationals Park on April 6, 2015 in Washington. Credit: Getty Images / Win McNamee

If the Mets are truly going to take over this town (New York), first they have to take over this town (Washington).

Monday's 3-1 victory over the Nationals on Opening Day was a terrific baby step, one that general manager Sandy Alderson thinks the Mets began taking last month in the hot sun of Florida.

The Mets want to turn this franchise around and turn Citi Field into the place to be this summer? They want to sell tickets and bury the Yankees in the back-page battle?

Then they have to beat the defending NL East champion Nationals. Which, even though the season is one game old, the Mets already have done six times in seven meetings in 2015.

Yes, we're counting exhibition games, because Alderson apparently is. The Mets went an NL-best 19-12 in spring training, including 5-1 against Washington.

"I thought the games in spring training were important," Alderson said. "Just to begin to kind of change, as I've said before, the perception of things."

Remember, the Mets went 4-15 against Washington last season. Turn just a few of those losses into victories and the 79-win Mets would have had their first above-.500 season since 2008. Just a few more than that, and the Mets would have been wild-card contenders.

In this year's Grapefruit League action, the players who were wearing Mets uniforms outscored the players who were wearing Nationals uniforms by a combined 48-23.

Many of those players from spring training were not at Nationals Park on Monday because they still are in Florida getting ready for minor-league seasons. But the Mets apparently will take confidence wherever they can get it.

No-hit for 5 2/3 innings by Max Scherzer, the Mets received a gift in the form of an inexplicably overpursued and undercaught pop-up by Nationals shortstop Ian Desmond.

It was what they did with the gift that should give Mets fans hope.

The Mets were trailing 1-0 when David Wright lofted a high pop-up to short right-centerfield with a man on first.

Washington second baseman Dan Uggla seemed to be settling under the ball when Desmond ranged over and called off the former Brave. Bad call. The ball ticked off Desmond's glove for a two-base error.

Scherzer, the $210-million free-agent signee, screamed in anger when the ball fell. But he just needed to retire Lucas Duda, who had struck out and fouled to third.

Scherzer got ahead 1-and-2 and had the big lefthanded hitter primed for the punchout. The 98-mph fastball was Scherzer's fastest pitch of the day. But it went back even faster into right-centerfield for a two-run single.

The Mets had their first hit, first runs and first "take that, Nationals" moment of the season. And then their first win.

"It definitely shows that we can compete," Duda said, "and compete with the best teams in the league."

Duda, who couldn't get together with the Mets on a contract extension, may have just seen his price go up.

The Mets' third run also was unearned because of Desmond's throwing error in the seventh, which was followed by Travis d'Arnaud's RBI triple.

"You just can't keep giving good teams outs," manager Terry Collins said. "We think we're a good team."

"Unearned" is a bookkeeper's note. The Mets earned the runs because they took advantage of Washington's errors. They earned the win because Duda was clutch and Bartolo Colon (obviously the right call for Opening Day, right?) was brilliant and the bullpen was fierce, even though the news that closer Jenrry Mejia has a sore elbow is a concern.

Again, one win is a baby step. But if they follow yesterday's formula about 10 or 11 more times against the Nationals, and with the way the Yankees looked Monday, the Mets really could take over this town.

And this one, too.