All it took for the Mets to get healthy again was a visit from the National League’s best team.

Bartolo Colon out-pitched Jake Arrieta on Saturday night as the Mets beat the Cubs, 4-3, for a third straight victory in front of a packed house at Citi Field.

Just like that, the dispiriting sweep earlier in the week in Washington seems like a distant memory.

“This is a good indication of how we need to play the rest of the summer,” said Neil Walker, whose first inning, two-run homer off Arrieta helped set the tone.

The Mets scored four runs off the reigning NL Cy Young Award winner, who was coming off his worst start of the season.

Travis d’Arnaud delivered the other critical blow in the fourth, a two-run single that dropped into shallow center off the bare hand of second baseman Javier Baez, who had just entered the game.

It was set up by Arrieta’s two-out walk to Alejandro De Aza, who was in a 2-for-37 funk.

The play helped make a winner out of Colon (7-4), who hasn’t given up more than two runs in an outing since May 18 against Washington.

The only runs Colon allowed came on Anthony Rizzo’s monster home run in the top of the fourth.

Despite the solid outing, manager Terry Collins revealed Colon’s left leg stiffened up in the second inning and again when he was running to first on a fourth-inning groundout.

Collins said he isn’t concerned about the leg “yet,” and Colon added he had been dealing with the injury since he faced the Pirates on June 16.

Despite feeling it when he lands in his delivery, Colon remained effective.

After Colon’s departure, the Cubs drew closer in the seventh, when Eric Goeddel coughed up a solo shot to Ben Zobrist with two outs to make it 4-3.

Addison Reed came on to get Kris Bryant for the final out of the inning, fanning him to strand Jason Heyward at second.

“You trust guys that throw strikes,” Collins said. “That inning, with Heyward on, we’ve got to get Bryant out.”

The right-hander then struck out three more in the eighth to get the ball to Jeurys Familia, who tossed a scoreless ninth to pick up his 28th save of the year, as the Mets improved to 18-10 in one-run games.

Collins was confident Colon would be up to the task of facing Arrieta.

“This is a matchup he’s had 50 times,” Collins said. “I can’t tell you how many Cy Young Award winners [he’s faced] in his career … [and] he’s got one of those trophies on his mantle.”

While Colon lived up to Collins’ expectations, it was a rough night from the outset for Arrieta, who dominated the Mets in two outings during the regular season a year ago but got touched for four runs in five innings during Game 2 of the NLCS.

After Brandon Nimmo walked to lead off the bottom of the first, Walker turned on a 3-2 pitch and hit it off the right-field foul pole to give the Mets a quick 2-0 lead.

Arrieta retired 10 straight after a Yoenis Cespedes double but faltered again in the fourth.

The victory left the Mets looking for a sweep of Chicago on Sunday, after they dropped four in a row.

And thanks to the Nationals’ loss to Cincinnati on Saturday, the Mets are back to within five games of first place in the NL East.

“We want to finish it off [Sunday],” Collins said of the potential sweep. “We’re certainly, right now, playing pretty good.”