Match ends, Birmingham City 4, Leeds United 5.
Leeds United won an astonishing nine-goal thriller against Birmingham City at St Andrew's to go back top of the Championship.
But it was rough luck on Birmingham, who three times came from behind to level before Wes Harding's injury-time own goal.
"Every time Birmingham scored, we had the energy to go for one more goal," said Leeds United head coach Marcelo Bielsa.
Bielsa's men will now start 2020 top of the second tier thanks to morning leaders West Bromwich Albion losing just a few miles away at home to Middlesbrough.
It looked like it might be a stroll for Leeds when Helder Costa and Jack Harrison scored inside the space of six first-half minutes.
But 16-year-old Jude Bellingham scored with his first goal in over three months to reduce the arrears at half-time before Lukas Jutkiewicz levelled on 61 minutes.
Luke Ayling put Leeds back in front eight minutes later, but Jeremie Bela equalised for a second time.
Stuart Dallas then struck on 84 minutes, only for Jutkiewicz to level again - but Harding's own goal in the fifth minute of added time settled a classic contest.
Ninety-odd minutes, nine goals . . .
Although without 10-goal top scorer Patrick Bamford, who suffered a dead leg in the 1-1 Boxing Day draw against Preston, Bielsa's side took the lead on 15 minutes when they broke quickly from a Birmingham corner.
Harrison collected a loose ball after Liam Cooper nodded away Gary Gardner's header and surged upfield before threading Costa through to turn Max Colin and bury a low, left-foot shot to Connal Trueman's left into the bottom corner.
Harrison then made it 2-0 with his fifth goal of the season, a half volley that took a hefty deflection off Harlee Dean to wrongfoot Trueman, after being set up by Ezgjan Alioski.
But Bellingham fired home from 15 yards from Colin's cross before Blues levelled with the first meaningful chance of the second half.
Colin's corner was nodded goalwards by Kerim Mrabti at the far post and goalkeeper Kiko Casilla could only parry as far as Jutkiewicz, who nodded home.
Leeds were back in front when Ayling cut inside from the right flank, foxing Bela with one touch, and without any further challenge from any Blues player, was allowed to stride forward and, as the ball sat up kindly for him on the half-volley, he lashed a right-foot shot just inside the left upright.
Birmingham pegged them back again when Bela glanced in Pedersen's free-kick, only for the unmarked Dallas to hook home from Ayling's pass.
But, although Jutkiewicz stabbed home Bela's cross from close range in the 91st minute to make it 4-4, Harding fired into his own net under pressure from Ayling's cross.
Leeds are back in the Midlands on New Year's Day for their 'second v first' clash with Albion at The Hawthorns.
They will start the day level on points with Slaven Bilic's side, but with a better goal difference of just two.
Blues, who have slid to within eight points of trouble, are at home again - to bottom club Wigan Athletic.
Birmingham City head coach Pep Clotet told BBC WM:
"If you only think about the result, we're disappointed, because we came back three times against Leeds.
"But at the same time, after playing West Brom and Leeds at home in the last 15 days, we did see a lot of things we are looking for and need to be encouraged.
"We're missing a few players still and we look a bit vulnerable at the back. But it's about us showing this fighting spirit, resilience and good quality football, going toe-to-toe with the team that at the minute is on top of the league."
Leeds United midfielder Stuart Dallas:
"It's definitely one of the craziest games I've been involved in. So much emotion. We just had to step up and grind it out and hope that was it, but they just kept scoring.
"I'm just glad I was playing in it rather than watching it, but the crowd have definitely got their money's worth.
"The games are coming thick and fast now. We now have West Brom in three days' time, which is obviously going to be a massive game but we just have to concentrate on ourselves."
- 2HardingBooked at 48mins
- 22BellinghamSubstituted forMonteroat 74'minutesBooked at 90mins
- 20GardnerBooked at 39mins
- 7CrowleySubstituted forBelaat 68'minutes
- 18MrabtiBooked at 62minsSubstituted forGiménezat 74'minutes
- 10JutkiewiczBooked at 63mins
- 13CasillaBooked at 71mins
- 2AylingBooked at 88mins
- 43KlichSubstituted forBerardiat 86'minutes
- 14NketiahBooked at 73minsSubstituted forRobertsat 81'minutes
- 17Hélder Costa
- Keith Stroud
- Shots on Target
Second Half ends, Birmingham City 4, Leeds United 5.
Offside, Leeds United. Ezgjan Alioski tries a through ball, but Tyler Roberts is caught offside.
Own Goal by Wes Harding, Birmingham City. Birmingham City 4, Leeds United 5.
Corner, Leeds United. Conceded by Wes Harding.
Attempt blocked. Tyler Roberts (Leeds United) left footed shot from the centre of the box is blocked. Assisted by Jack Harrison with a cross.
Jefferson Montero (Birmingham City) is shown the yellow card.
Goal! Birmingham City 4, Leeds United 4. Lukas Jutkiewicz (Birmingham City) left footed shot from the left side of the six yard box to the bottom left corner. Assisted by Jérémie Bela with a cross.
Luke Ayling (Leeds United) is shown the yellow card.
Corner, Birmingham City. Conceded by Ezgjan Alioski.
Substitution, Leeds United. Gaetano Berardi replaces Mateusz Klich.
Goal! Birmingham City 3, Leeds United 4. Stuart Dallas (Leeds United) left footed shot from the centre of the box to the top right corner. Assisted by Luke Ayling.
Goal! Birmingham City 3, Leeds United 3. Jérémie Bela (Birmingham City) header from the centre of the box to the top left corner. Assisted by Kristian Pedersen with a cross following a set piece situation.
Foul by Liam Cooper (Leeds United).
Lukas Jutkiewicz (Birmingham City) wins a free kick on the right wing.
Attempt saved. Ezgjan Alioski (Leeds United) left footed shot from outside the box is saved in the top centre of the goal.
Substitution, Leeds United. Tyler Roberts replaces Eddie Nketiah.
Eddie Nketiah (Leeds United) wins a free kick in the attacking half.
Foul by Wes Harding (Birmingham City).
Corner, Leeds United. Conceded by Wes Harding.