The Indianapolis Colts were very aware they were becoming "a punch line" in the NFL ahead of Saturday's game against the Minnesota Vikings, in which they sought to respond.

Remarkably, the AFC South strugglers only made matters worse as they threw away a 33-0 lead in a record-breaking defeat.

The Colts initially had an answer to their critics, building a big lead against the high-flying Vikings on the back of a brilliant first-half defensive performance.

But the latest miserable episode in this Indianapolis season – described as "heartbreaking" by interim coach Jeff Saturday – swiftly followed.

The Vikings rallied for the biggest comeback win in NFL history, first taking the game to overtime via a 22-point fourth quarter before Greg Joseph's field goal clinched victory and the NFC North title.

The Colts had given up 33 points in the fourth quarter of the previous week's defeat to the Dallas Cowboys, a desperate franchise record.

Indy's woes are on both sides of the ball, though, as Frank Reich's firing earlier this year came after a Week 9 loss to the New England Patriots in which 121 yards of total offense represented their worst performance since 1997.

"You give it literally everything you have, you've been through a whole lot of adversity," said Colts linebacker Zaire Franklin.

"We've been hearing everybody talk about us like we're a punch line and we took that very personally. I think you could tell by how we came out and played.

"For the game to go the way it did at the end, it's definitely a tough, tough pill to swallow."