The Detroit Lions have suffered down the years but they experienced a new level of pain on Sunday as the team blew a 24-7 halftime lead in the NFC Championship Game.

Their conquerors, the San Francisco 49ers, will play the Kansas City Chiefs in the Super Bowl after the defending champions beat the Baltimore Ravens in the AFC Championship Game earlier on Sunday.

The Lions, looking to make the Super Bowl for the first time in their history, took an early 14-0 lead against a 49ers team known for their struggles in clawing back deficits. That lead grew to 17 points coming into the third-quarter before a breathtaking catch from Brandon Aiyuk sparked a 49ers comeback that will haunt the dreams of Lions fans for years to come.

“We played as bad of a first half as we could, but we were still within 17. There’s plenty of points there you can make up,” Niners coach Kyle Shanahan said. “The D shut them out there in the second half and this dude right next to me [quarterback Brock Purdy] made it happen.”

San Francisco mounted the fourth comeback ever from 17 points down or more in a conference title game thanks to some big plays by Purdy and bad mistakes from the Lions, including two failed fourth downs in field-goal range. Detroit fell short of reaching their first Super Bowl in franchise history.

After being questioned about whether he could lead a comeback, Purdy has now done it twice in as many weeks. He engineered a game-winning drive in the fourth quarter to beat Green Bay last week and then had an even bigger comeback against the Lions.

Christian McCaffrey had two TD runs and little-used backup Elijah Mitchell scored on a three-yard run to make it 34-24 with 3:02 to play as the Niners got over the conference title game hump after losing the past two seasons.

Related: Mahomes and Kelce combine to beat Ravens and send Chiefs back to Super Bowl

The Niners blew a 10-point lead in the fourth quarter of the NFC Championship Game against the Los Angeles Rams two years ago and then were forced to play much of last year’s title game loss at Philadelphia without a functioning quarterback after Purdy injured his elbow on the opening drive and fourth-stringer Josh Johnson left with a concussion early in the third quarter.

But San Francisco managed to make the long journey back to this stage and now are in position to deliver the franchise their record-tying sixth Super Bowl title and first since the 1994 season.

A magical season for the Lions ended in heartbreak. Detroit remain the only team to play every season of the Super Bowl era without reaching the ultimate game. This looked like it could be the year to end that drought when Detroit won back-to-back playoff games after winning just one in the previous 56 seasons.

But the Lions couldn’t finish the job despite holding the 24-7 halftime lead.

San Francisco settled for a field goal on the opening drive of the second half before the game completely flipped in a four-minute span.

Detroit coach Dan Campbell opted to go for it on fourth-and-two from the San Francisco 28, but Josh Reynolds couldn’t hold onto a pass from Jared Goff, leading to a turnover on downs.

The Lions then seemed to have a potential interception when Purdy’s deep pass hit Kindle Vildor in the face mask, but the ball popped up and was caught for a spectacular 51-yard gain by Aiyuk. Purdy found Aiyuk three plays later for a six-yard score.

“Before the game, a ladybug landed on my shoe. And you all know what that means,” Aiyuk said. “That’s all I can say. Other than that, I don’t know.”

Jahmyr Gibbs then fumbled on the next play from scrimmage, setting up a one-yard run by McCaffrey to tie the game at 24-24.

It only got worse from there for the Lions with Reynolds dropping another pass on third down, leading to a punt that Detroit had a chance to down at the one-yard line but botched.

Purdy then drove the Niners to a 33-yard field goal by Jake Moody and their first lead of the game.

Campbell bypassed a chance at a game-tying field goal on fourth-and-three from the Niners’ 30 midway through the fourth quarter. Goff threw an incomplete pass and the Niners drove to the insurance touchdown.

Goff added a TD pass to Jameson Williams with 56 seconds to play, but the 49ers recovered the onside kick to seal the win. Goff finished 25 for 41 for 273 yards and a touchdown.