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The Cincinnati Bengals produced a stunning comeback to upset the Kansas City Chiefs 27-24 and book a first Super Bowl appearance in 33 years.
Trailing 21-3, Cincinnati scored 21 unanswered points before the Chiefs landed a field goal as time expired.
But Chiefs quarterback Patrick Mahomes was intercepted in overtime and Evan McPherson kicked Cincinnati to victory.
The San Francisco 49ers meet the Los Angeles Rams later on Sunday to decide Cincinnati’s Super Bowl 56 opponents.
Defending AFC champions Kansas City were heavy favourites to book a third successive Super Bowl appearance and appeared to be cruising to victory when they opened up a daunting 18-point lead.
But the Bengals made a crucial stop just before half-time to limit their deficit, which quarterback Joe Burrow clawed back during the second half as his opposite number Mahomes began to go awry.
Before this season, Cincinnati – who were the worst team in the NFL two years ago with a 2-14 record – had not won a play-off game in 31 years but they have now won three in quick succession.
The classic game of two halves
Only 15 months separate Burrow and Mahomes in age but the latter has already won two AFC titles and a Super Bowl, while this year has marked the Bengals quarterback’s first post-season campaign.
That difference in experience appeared to be telling in the first half as Mahomes led the Chiefs to three touchdowns on their opening three drives as Burrow struggled to get a foothold.
A 10-yard pass to Tyreek Hill opened the scoring and although Cincinnati responded with a McPherson field goal, the Chiefs quickly added two more touchdowns.
Wide receiver Mecole Hardman was central to both, reeling in a 44-yard Mahomes pass on a drive that ended with a touchdown for tight end Travis Kelce before scoring himself with a smart catch from an improvised close-range bullet.
But AFC North champions Cincinnati have been arguably the NFL’s most improved team this season, and Samaje Perine’s 41-yard catch and run reduced their deficit to 11 points.
The game turned on the brink of half-time as, with five seconds remaining, Kansas City turned down the chance of a close-range field goal to go for a touchdown and Hill was tackled short of the line.
That decision proved costly as Kansas City were unable to regain the momentum after the interval with the previously-unflappable Mahomes coming under regular pressure.
McPherson hit another field goal and, after Mahomes was picked off by BJ Hill, Cincinnati levelled as Burrow found Ja’Marr Chase for a touchdown and Trent Taylor for a two-point conversion.
McPherson converted a 52-yard kick to give the Bengals the lead for the first time but Mahomes recovered his composure to lead a solid Chiefs drive that ended with Harrison Butker’s last-second 44-yard field goal.
Butker had forced overtime the previous week as Kansas City edged out the Buffalo Bills in overtime but there was to be no repeat as Mahomes was picked off by Vonn Bell when throwing downfield.
Rookie kicker McPherson, just as he had in the Bengals’ previous post-season wins over the Las Vegas Raiders and Tennessee Titans, proved the hero by kicking the decisive field goal from 31 yards.