WASHINGTON — If nothing else, the Mets can aim to avoid the NL East cellar. 

They have trended in the right direction lately, and their 11-5 victory over the Nationals on Tuesday night only helped.

The Mets’ fourth victory in five games moved them 2 ½ lengths ahead of Washington for last place, with a final head-to-head meeting between the division foes awaiting on Wednesday. 

Jose Quintana’s second straight superb start, combined with five home runs by the Mets, turned this one into an early runaway. 

There was plenty for the Mets to like, including contributions from all four of their heralded rookies — Francisco Alvarez, Mark Vientos, Brett Baty and Ronny Mauricio — who were together in the starting lineup for the first time.

Brandon Nimmo also continued his career-year in power production with a two-homer game. 

“We are trying to see what we have in store for next year,” Nimmo said. “There might be a world where we sneak into the playoffs somehow, I don’t know. But right now I am trying to see Mauricio, trying to see Baty, Alvarez … what they do on a daily basis and be around them and mentor them and same with the young pitchers we have. I couldn’t care less if we finish last in the division or second-to-last.

“I am looking toward, ‘How can we make this team as good as possible for next year?’” 

Manager Buck Showalter said he was happiest about the strong defense the Mets received from the rookies. 

“You could tell it was a big night because you know how close they are,” Showalter said. “They have been through a lot in the minor leagues together and I was happy with how they played defense more than anything. Brett had a good night at third base, [Mauricio] made a couple of good plays and Alvy has been pretty solid behind the plate blocking [pitches].” 

The lefty Quintana allowed one earned run on four hits with four strikeouts and one walk.

That followed his performance against Texas last week, in which he delivered six shutout innings. 

The Mets jumped on Patrick Corbin in the first inning and never looked back.

After a replay review determined Vientos had been hit by a pitch with one out and a runner on, Alvarez delivered a three-run homer that gave the Mets a 4-0 lead. 

Alvarez has had the ultimate mixed-results season.

The rookie catcher entered Tuesday with a .211/.285/.426 slash line, 21 homers and 48 RBIs in 104 games. His home run was his first since Aug. 1. 

“This season is like a mountain: You go up and sometimes you slip down,” Alvarez said through an interpreter. “Not everyone is always going to stay at the same level and keep going up and up all year. You just have to try to remain consistent with your preparation and that is all you can really do.” 

Said Showalter: “[Alvarez] is one of those guys that about the time you start counting him out, he pops one. I think it’s because he never gives in.” 

Nimmo and Francisco Lindor singled in succession to begin the game. Following Jeff McNeil’s sacrifice bunt, Pete Alonso’s sacrifice fly gave the Mets a 1-0 lead.

After Vientos was plunked, Alvarez homered. 

Lindor homered leading off the third inning to extend the Mets’ lead to 5-1.

Baty blooped a two-run single later in the inning, after Vientos had tripled and Alvarez had walked.

Alvarez then swiped second for his first career stolen base. 

“[Corbin] is a lefty and he was lifting his leg pretty high there, so I figured I could go,” Alvarez said. 

Nimmo’s homer in the fourth inning buried the Nationals in an 8-1 hole. 

Alonso smashed the Mets’ fourth homer of the game, a solo shot in the fifth that extended the lead to 9-1. The homer was Alonso’s third in two games and gave him 42 for the season, three behind the Braves’ Matt Olson for the major league lead. 

Mauricio’s RBI single in the eighth extended the Mets’ lead to 10-1.

After the Nationals scored four times against Sam Coonrod in the eighth, Nimmo homered in the ninth to give the Mets their final run.