Up and down all season, cornerback DeAngelo Hall is riding high again. The Washington Redskins’ mercurial playmaker made another big play. At least for a game, Hall got his swagger back.

Chances are, it could be gone again next week. That’s just how this strange ride has been for him. But for the moment anyway, Hall rediscovered the right path Sunday and made a significant, positive contribution in Washington’s surprising 23-10 victory over the New York Giants.

A week after the Giants appeared to salvage their season with an impressive overtime road victory against the Dallas Cowboys, their road became more difficult with Sunday’s stinker at MetLife Stadium. Hall was a leader on defense as the Redskins did a lot to potentially ruin everything for the Giants.

He performed well in coverage. He played hard until each play was finished. Hall did all the Redskins would expect from a veteran defensive co-captain.

And in the third quarter, Hall added another moment to his career highlight tape. His sensational one-handed catch on quarterback Eli Manning’s attempted deep pass to wide receiver Hakeem Nicks was as fine an interception as you’ll see in the NFL this season.

“We call that the interception coverage,” said cornerback Josh Wilson, who had one of the Redskins’ three picks. “Looks like [Hall] did a great job in it.”

Then, Hall did what he has done better than any Redskins defensive player since he joined the team in 2008, gaining 26 yards on a nifty return along the sideline in front of cheering Redskins coaches and players. The celebration he ignited was one of many upbeat moments for the Redskins, who completed a two-game season sweep of their NFC East rivals.

“With them having the ball first, we came outta halftime saying we knew we had to make a play,” said Hall, whose interception occurred on the second play from scrimmage in the third quarter.

Four plays after Hall’s interception, place kicker Graham Gano made a 43-yard field goal to extend Washington’s lead to 17 points with just under 12 minutes remaining in the quarter. Gano’s third three-pointer all but ended the game.

Oh, there was still plenty of time for Giants — who briefly occupied first place in the division after defeating Dallas in Week 14 — to rally Sunday if they were playing somewhat decently. The Giants, however, were awful, and they were finished.

After committing two egregious mental errors in Washington’s previous game, Hall helped to finish off the Giants early. He returned to a good place — no matter how long he stays there.

“D-Hall was elected a captain for a reason,” said inside linebacker London Fletcher, who shares leadership duties with Hall. “He has great leadership qualities, and the thing you always want him to do is lead in the right way.

“We understand he got a little frustrated [in the Week 14 loss to the New England Patriots]. Sometimes, in the heat of the battle, that can happen to you. But that’s not the way you want to look. . . . We want to see him like he played today — making plays and leading us the right way.”

Last week, on New England tight end Rob Gronkowski’s eye-opening 49-yard reception in the first quarter, Hall, who said he thought Gronkowski stepped out of bounds, did not help safeties Reed Doughty and DeJon Gomes bring down the imposing player.

In the third quarter, Hall, upset about being called for holding, picked up the official’s flag and tossed it. He was assessed 20 yards in penalties on one play.

The Patriots scored touchdowns on both possessions.

“You got to look at yourself and say, ‘Hey, I got to play at a higher level,’ ” Coach Mike Shanahan said. “That’s what he did today. . . . The one interception he made was a fantastic play.”

Hall was hard on himself after giving up big plays late against Dallas that helped the Cowboys sweep the Redskins this season. In a moment of frustration, Hall said if he were in charge of the Redskins, he would release himself.

Hall has had high highs, too.

He was selected the NFC’s defensive player of the week after he defended six passes, made five tackles and picked off a pass during the Redskins’ 23-17 Week 12 road victory over the Seattle Seahawks.

And opposing coaches and players have praised Hall often for his play. “I just expect more out of myself. A couple of plays, I feel like I should have made, would have gave us a chance to win that game [against the Patriots]. But I feel like I’m playing good football, man. I’ve just been extra critical of myself at times.”

Reality is, with today’s NFL rules, there’s no longer such a thing as a true shutdown corner. The league’s leaders and their high-paying television partners enjoy big passing plays. It’s good for business.

Hall is the Redskins’ best corner and he makes plays. Sure, he’s temperamental at times. But the Redskins definitely need him.

“If you look at his body of work as a whole, he’s having a pretty solid season,” special teams captain Lorenzo Alexander said. “Of course, when you’re a corner, and you’re out there on an island and give up a big play, people think you’re the worst thing ever. But D Hall is a competitor. He’s gonna continue to make big plays.”

It was a good game for Hall. Maybe he’ll even make it two in a row.

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