The Mets insist they still have a run in them. If they’re going to go on one, they have to beat certain teams, with the rebuilding Washington Nationals being one of them.

They took care of business Wednesday at Nationals Park with a 9-1 win to complete a three-game series sweep. It was their fifth win in the seven games since they held a players-only meeting.

Luis Severino gave the Mets some much-needed length with eight innings of one-run baseball. A beleaguered bullpen didn’t have to worry about a save situation or any tense late-game pitching performances with the Mets beating up on left-hander Patrick Corbin and right-hander Jordan Weems, taking all nine runs off of the two Washington hurlers, including a six-run sixth inning that sunk the Nats (27-34).

“We won three games in a row and we got a chance to win four,” Severino told reporters after the game. “When we combine hitting and pitching at the same time, it’s huge for us. We have this mentality now that we have to go out there and give 100 percent every time.”