Before their improbable loss to the Lions last Sunday, the 2021 Vikings had established at least a seven-point lead in each game, and had a 5-6 record to show for it. So, it’s not as if Mike Zimmer’s team has been immune to heartbreaking losses.

On Thursday night, Zimmer and his team came all too close to making regular-season NFL history. When Greg Joseph kicked a 25-yard field goal with 6:15 left in the third quarter, Minnesota had a 29-0 lead against a Steelers offense that couldn’t get anything going, and a Steelers defense that allowed Dalvin Cook to run through it with absolute impunity.

And then, as has happened all season, things changed all too quickly for the Vikings.

Pittsburgh scored four touchdowns in less than a quarter of football, Kirk Cousins threw two interceptions to cornerback Ahkello Witherspoon, and Minnesota managed just one more touchdown — a 62-yard touchdown pass from Cousins to receiver K.J. Osborn.

It was that play that saved the Vikings from the wrong side of the biggest regular-season comeback in NFL history.

It put the Vikings up, 36-20, and gave them enough room to withstand Ben Roethlisberger’s 15-yard touchdown pass to tight end Pat Freiermuth with 4:14 left in the game.

The Vikings were unable to get past their own 45-yard line on their next drive, but when Jordan Berry executed an outstanding punt to pin the Steelers at their own three-yard line, you would think that even the Vikings were safe.

Not so fast, as they say. Roethlisberger carved Minnesota’s defense right up on the Steelers’ last drive, and with three seconds left in the game, he threw an absolute time to Freiermuth that the rookie just couldn’t hold onto. Vikings safety Harrison Smith saved what would have been a tie with a two-point conversion.

If the Steelers had scored the touchdown and two-point conversion at the end of regulation, and won in overtime, it would have marked the biggest comeback in any regular-season game in NFL history, topping the 1980 49ers, who beat the Saints, 38-35, after trailing, 35-7 in the second quarter.

Fortunately, the 49ers had a second-year quarterback named Joe Montana.

The biggest comeback in NFL history belongs to the Buffalo Bills, who roared back from a 35-3 deficit against the Houston Oilers in the wild-card round in the 1992 season.

Cook, who finished his day against the Steelers with 205 rushing yards and two touchdowns on 27 carries, seemed exhausted by the ordeal — and by the fact that these things just keep happening.

“We keep asking ourselves why we keep putting ourselves in this position,” he said after the game. “We’re a better team than these games have been telling. We’ve got to figure out a way to get out of that funk we’re in at the end of a game.”

“A relief,” Cook said of the feeling after the final play. “That’s been us all year. Living and dying by that last drive. We’ve got to figure it out. We’re going to keep trying to figure this our.”

It’s hard to say what exactly has befallen these Vikings, and why they’re unable to close things out, but they nearly did it at an historic level on Thursday night.