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

5. CB: Jake Clarke-Salter
Jake Clarke-Salter is now a regular for Championship club Birmingham City, on loan from Premier League Chelsea, and has also spent time on loan at Bristol Rovers and Vitesse. Photo: Dean Mouhtaropoulos

6. CB: John O'Shea
After retirement as a player with Championship club Reading in 2019, John O'Shea joined the backroom team at the club as a first-team coach. Photo: Nigel Roddis

7. CM: George Honeyman
George Honeyman now plays for Sunderland's League One rivals Hull City, who are battling for promotion back to the Championship. Photo: Jack Thomas

8. CM: Lee Cattermole
Lee Cattermole was released by VVV-Venlo in 2020, shortly after the season was abandoned as a result of the coronavirus pandemic. Cattermole has since retired and recently featured as a pundit on Sky Sports during Sunderland's win against Ipswich Town. Photo: Mark Runnacles