SANTA CLARA, Calif. -- Poor Detroit.

It's one thing to lose a game, even a championship tilt that had so much promise.

But to lose like the Detroit Lions crumbled at Levi's Stadium on Sunday? Now that's just cruel. The Lions built a 17-point halftime lead against the San Francisco 49ers and still lost.

What a gigantic tease and ... epic collapse.

And as the Lions fell, 34-31, in a wild NFC title game, there were no kneecaps to bite.

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Instead, the 49ers stormed back to match the biggest comeback victory in NFC championship game history and claimed a berth in Super Bowl 58 for a Super rematch against the Kansas City Chiefs. Whew.

Grit, meanwhile, took a serious punch to the gut.

"You feel like you got your heart ripped out," Lions coach Dan Campbell lamented.

Campbell knows. As much as the top-seeded 49ers demonstrated tremendous resilience to finally claim a Super Bowl berth after losing in the previous two NFC title games -- and a week after barely surviving against the Green Bay Packers in the NFC divisional playoffs -- this one felt more like a big, fat, ugly Lions loss.

I mean, how does a team rush for 148 yards in the first half -- more than the Kyle Shanahan-coached 49ers have allowed in an entire game -- and still lose?

How does a team with all of those weapons get shut out for all but the final minute of the second half when a Super Bowl berth is at stake?

In many ways, it was so Detroit. For all that has changed with the culture under Campbell, the Lions reverted back to the disappointing team that longtime followers had hoped was a thing of the past.

Campbell insisted otherwise.

"That's not like us," he said. "We had plays to be made that we just didn't make (like) we normally do."

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Anatomy of Lions' meltdown

Now, they'll have an entire offseason to process the anatomy of a meltdown that included:

-- 49ers receiver Brandon Aiyuk's acrobatic 51-yard catch early in the third quarter, with shades of Pittsburgh Steelers Super Bowl legend Lynn Swann. It was an omen. The ball ricocheted off Kindle Vildor as Aiyuk fell to the turf, advancing the football to the 6-yard line. Three plays later, Brock Purdy stepped up in the pocket and fired a 6-yard TD pass to Aiyuk.

-- On the first play of the ensuing drive, Lions rookie running back Jahmyr Gibbs fumbled. Arik Armstead recovered for the 49ers at Detroit's 24-yard line. It set up the 1-yard TD run from Christian McCaffrey that tied the game at 24.

-- Some serious second-guessing of Campbell. Twice in the second half, Campbell went for it on fourth-and-short rather than attempting field goals. Midway through the third quarter on a fourth-and-2 from the 49ers' 28, the Lions passed up a 46-yard field-goal try for a Jared Goff pass to Josh Reynolds that fell incomplete. A trey would have pushed the lead back to 17 points and made it a three-possession game.

In the fourth quarter, trailing by three, Campbell passed on a 48-yard try that might have tied the game. Instead, they went for it on fourth-and-3 from the 30. Goff was flushed from the pocket, mustering a throw to Amon-Ra St. Brown that fell in the dirt ... way short.

"I wanted to get the upper hand back," Campbell said of the latter case. "It's easy hindsight, and I get it. But I don't regret those decisions. And that's hard. That's hard because we didn't come through.

"I understand the scrutiny I'll get. That's part of the gig, man."

The reversal of fortune was so pronounced. The tough catches the Lions made in the first half, they mishandled in the second half. Case in point: Reynolds dropped a third-and-9 throw from Goff late in the third quarter. On the punt that followed -- a 74-yarder from John Fox -- Chase Lucas barely stepped in the end zone while trying to down the ball inside the 1-yard line. Touchback.

Those were the breaks.

By that time, school was out. The momentum had shifted. After Campbell passed up the field goal for a second time, the 49ers took possession and marched 70 yards on a drive capped by a 3-yard touchdown from Elijah Mitchell, and it was pretty much ballgame. The 49ers were up by 10.

The 49ers are headed to Las Vegas, with a quarterback, Purdy, who entered the NFL last season as Mr. Irrelevant, leading a historic comeback.

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But the flip side of this is just as compelling. The Lions finally had it in their hands -- the first Super Bowl berth in franchise history -- and let it slip away.

"That feeling that we all had walking off of that field, I don't think any one of us want to feel that again," St. Brown said.

In his postgame message, Campbell told his players that may have been their only shot. He could be right.

"Do I think that? No," he said. "Do I believe that? No. But I know how hard it is to get here. I'm well-aware, and it's going to be twice as hard to get back to this point next year. That's the reality."

And it's a reality check that's tougher to swallow for the way it went down.