SANTA CLARA, Calif. -- As they trudged to the locker room at halftime down 17 points to the Detroit Lions, their season's end seemingly just 30 minutes away, the San Francisco 49ers' range of emotions wasn't hard to comprehend.
The Lions had just pushed the Niners all over the field for the first two quarters and frustration didn't do it justice. On the light side, running back Christian McCaffrey called for focus. Coach Kyle Shanahan said his team was angry. Defensive end Nick Bosa described it as embarrassing.
For a proud, veteran team playing in its fourth NFC Championship Game in five years and third in as many seasons, no amount of halftime prodding was going to provide an instant fix.
"Regardless of any of that stuff, we're not going out like this," Shanahan said. "We've got to be a lot more aggressive here in the second half in everything we do, offensively, defensively, special teams. ... The guys didn't want today to be the last day."
For a team that spent most of the season running away and hiding from opponents by jumping out to big leads, the 49ers have turned this postseason run into a testament to their resolve.
That was writ large Sunday night when the 49ers erased that 17-point deficit in just eight minutes of game time, rattled off 27 consecutive second-half points and surged to a stunning 34-31 win to claim the franchise's eighth NFC championship, tied for the second most in league history. It tied for the biggest comeback in an NFC Championship Game ever with the 2012 Niners, who rebounded from down 17 to beat the Atlanta Falcons.
The victory punched San Francisco's ticket for Super Bowl LVIII at Allegiant Stadium in Las Vegas and set a rematch against the same Kansas City Chiefs they faced in Super Bowl LIV.
"It's perfect," Bosa said. "It's perfect and they're as great as an organization, coach, quarterback as there is, and they were down, not looking great this year, either. They're playing their best ball now, so it's going to be a big challenge."
To earn that opportunity, the Niners had to overcome what Shanahan said was a half as bad as any his team played this season. Detroit outgained San Francisco 280 to 131, picked up 18 first downs, limited the Niners to 4.7 yards per play and came away with quarterback Brock Purdy's first career postseason interception.
The Lions' physical dominance was apparent in their three touchdowns and 148 yards on 21 carries, including 5.4 yards per carry before contact.
"It was the way we were down," Shanahan said. "They were kind of having their way in the run game. We weren't getting much in our run game, either. ... That would have been a real rough way to end it if we couldn't have played better with our group."
The Niners proved in last week's comeback victory against the Green Bay Packers that even though they've won most of their games in blowout fashion, they're also capable of fighting back when they're on the ropes. The Niners are now one of two teams -- along with the 1994 San Diego Chargers -- to engineer multiple seven-plus-point second-half comebacks prior to reaching the Super Bowl.
After managing a Jake Moody field goal to open the third quarter, the Niners got the ball back when Detroit went for it on fourth-and-2 at San Francisco's 28 and quarterback Jared Goff's pass fell incomplete.
Two plays later, the Niners got the break and the spark that kicked their comeback into overdrive. On first-and-10 from their 45, Purdy got the look he wanted with receiver Brandon Aiyuk one-on-one with Lions cornerback Kindle Vildor. Purdy let it fly but Vildor managed to stay deep and looked poised for the interception.
Instead, the ball clanged off Vildor's facemask, bounced into the air and the alert Aiyuk hauled it in for a 51-yard catch. Three plays later, Aiyuk caught a 6-yard touchdown to cut the deficit to seven.
"To have an explosive play like that was huge in that moment," Purdy said. "BA did a great job with tracking the ball all the way and making a huge play for us. He's a baller. That was clutch on his part."
Aiyuk's big catch wouldn't be the only bounce that turned the game in San Francisco's favor. On Detroit's next play from scrimmage, safety Tashaun Gipson hit Jahmyr Gibbs and forced a fumble that Arik Armstead recovered. Four plays, including the first of two 21-yard scrambles by Purdy, got the Niners into the end zone again and they had quickly turned a 24-7 deficit into a tie at 24.
Meanwhile, the 49ers' defense adjusted, allowing 34 rushing yards in the second half, coming up with two fourth-down stops and yielding just seven points. Detroit tightened up, dropping catchable passes, coughing up the fumble and struggling to keep drives alive.
By the time it was over, the Niners had scored 27 straight, the fourth-most consecutive points by a team in a conference championship game that was trailing entering the run, according to the Elias Sports Bureau. It was also the most by a team that was down more than 10 points.
"That's the cool thing about football," tight end George Kittle said. "For us to be able to hunker down and start to fire on all cylinders, that's what you see, an explosive offense, a very talented defense that flied around and hits people and causes turnovers and then our special teams make plays when they need to."
In addition to the 27 second-half points, the Niners rolled up 282 yards of offense while averaging 7.4 yards per play. After accounting for just 92 yards from scrimmage with an interception in the first half, Purdy threw for 174 and a touchdown and ran for 49 yards in the final 30 minutes.
Both of Purdy's 21-yard scrambles led to touchdowns.
"The guys didn't want today to be the last day."49ers coach Kyle Shanahan
"I thought it was the difference between winning and losing," Shanahan said. "He made some big plays with his legs, getting out of the pocket, moving the chains on some first downs, some explosives. He competed his ass off today. Wasn't easy on any of us. He kept grinding, was unbelievable there in the second half."
With the victory, the Niners sit alone in NFL history with 38 playoff wins, surpassing the New England Patriots and Packers.
After what Shanahan said will be some time to celebrate Sunday night and into the wee hours of Monday, the Niners will turn their attention to Patrick Mahomes and the Chiefs. That they will get a chance to atone for the loss to Kansas City in their last Super Bowl appearance in 2020 is the icing on the cake. The Niners led that game by 10 and had the ball with 8:53 to go but fell 31-20 as the Chiefs rattled off the final 21 points.
Kansas City has since been back to the Super Bowl two previous times, winning one of those, and will enter this one as the defending champion. The 49ers opened as 2.5-point favorites at ESPN BET, but the lined dipped to -1.5 within 20 minutes after being posted and was as low as -1 at some sportsbooks Sunday night. The total opened at 47.5.
San Francisco's core of veterans has been here before but still longs to break through. To do it, the Niners will have to do what they couldn't just four years ago.
"We accomplished what we wanted to accomplish," fullback Kyle Juszczyk said. "We're back in the Super Bowl and now we have one more goal to go. We have to win this game."