The match was dubbed ‘Bristanbul’ after Liverpool’s famous Champions League final comeback against AC Milan in Instanbul back in 2005.
The Robins, who had won just once in 2018, were three goals ahead inside 37 minutes as the Black Cats under Chris Coleman capitulated.
Aden Flint poked City in front before two close-range finishes from Famara Diedhiou prompted some away fans to leave Ashton Gate early.
But, after Josh Brownhill's own goal and Aiden McGeady's strike, Marlon Pack diverted into his own net for 3-3.
It capped an amazing final 20 minutes for Sunderland, whose supporters had greeted the half-time whistle with boos and chants of "you're not fit to wear the shirt" towards their own players.
Interestingly, current Black Cats boss Lee Johnson was head coach at Bristol City and after the game said: “It's probably poor decision-making by me. I have to hold my hands up and say, tactically, I got it wrong in the second half.
“I should have settled for 3-0. I probably got excited, and felt they were there for the taking.
“We had chances but we crumbled. I should have given the lads a bit more help and put another midfielder on at 3-1, and changed it up a bit.
“So, my fault, and apologies. To lose those two points is very, very frustrating.”
But where are the Sunderland players named in the squad back in 2018 now? Scroll down to take a look:

. SUNDERLAND, ENGLAND - APRIL 21: Chris Coleman manager of Sunderland during the Sky Bet Championship match between Sunderland and Burton Albion at Stadium of Light on April 21, 2018 in Sunderland, England. (Photo by Nigel Roddis/Getty Images )
Chris Coleman during the Sky Bet Championship match between Sunderland and Burton Albion at Stadium of Light on April 21, 2018. Photo: Nigel Roddis

. GK: LEE CAMP
Late last year, Lee Camp signed for Championship club Coventry City on a two-month contract as injury cover but left when the deal expired without having been needed to play. He is now a free agent. Photo: Lynne Cameron

. RWB: Billy Jones
Billy Jones is currently at Sunderland's League One rivals Crewe Alexandra on loan from Championship side Rotherham United. Photo: Jan Kruger

. LWB: Bryan Oviedo
Bryan Oviedo now turns out for Danish Superliga club Copenhagen. Photo: PAUL ELLIS

17. SUB: Lynden Gooch
Lynden Gooch is still at Sunderland under Lee Johnson, having played for the club in the Premier League, Championship and League One. Photo: Bryn Lennon

18. SUB: Ethan Robson
Ethan Robson now turns out for Sunderland's League One rivals Blackpool, where he was joined by Black Cats loanee Elliott Embleton last month. Photo: Alex Burstow

19. MANAGER: Chris Coleman
Chris Coleman most recently served as the manager of Chinese Super League club Hebei China Fortune from June 2018 until May 2019 but is now out of work. Photo: Jack Thomas