Fulham head coach Scott Parker called for VAR to be introduced into the Sky Bet Championship after believing his side were denied a late penalty by referee Jeremy Simpson.
Neeskens Kebano appeared to be clipped by City's Callum O'Dowda, only for referee Simpson to wave away appeals from the Fulham players mobbing him, before the midfielder headed against the crossbar in stoppage time.
Parker was convinced that Simpson had erred in not awarding a spot-kick. "I think so," he said.
"The referee has obviously made a big mistake and that can happen, human error. That's when you want VAR in the Championship. Probably it is an instant reversal of the decision.
"I think you come to football matches, and I played for 20 years, and you see instances developing.
"As that play was developing, as Neeskens got in front of him and you saw the guy coming across him, you think: 'You need to look for a penalty here, he is going to clip the back of his leg.' That's how I see it.
"But I am proud of my team. Three or four weeks ago we lost to Hull City here and the stadium cleared out. The fans lost a bit of belief that we could get back in it and I sensed the players did as well.
"But at 2-0 down today with 10 minutes on the clock, we were in the ascendancy and didn't give up, they kept going.
"On another day, the one that hits the bar, the penalty decision, it could turn a different way. I'm proud of the players today."
Bristol City boss Lee Johnson said: "I haven't seen the penalty back but I don't need to. I spoke to our player, Callum O'Dowda, and he felt he pulled away and pulled out. Obviously that is a player's word for it and I'm sure that if the roles were reversed then I would have a different opinion.
"It was a heart-in-the-mouth moment. But we deserved the win. In the first half, I thought we were absolutely outstanding and we limited them to not a lot and created a couple of really good chances ourselves. The second goal was as good as you will see at this level."
Speaking about the four-man move for the second goal, Johnson added: "As a coach I am delighted because there was a bit of everything in that goal, a bit of individual brilliance, a bit of tactical play, a bit of strength and it was an important time to get it."
He also praised Niclas Eliasson, whose cross created the opening goal.
"There were a few things he didn't get on the end of but we know his talents," Johnson said.
"You recruit players for their individual brilliance, especially wide men, but for me the way he has grown since we signed him as a young boy from Sweden, nurtured him physically and tactically, to see him become a man in his game at Championship level is full credit to him and very nice to see."