Forest completed the job, though, and Nuno was beaming as he reflected on the epic tie.
Nuno said: “This is the FA Cup, it is so special and that is why we are so happy and proud to keep continuing and fighting for something that is so huge for us.
“To fight for a trophy, with the history of the club we have to keep on fighting and try to deliver.
“I’m so happy that we got through and the players never gave up.”
Bristol City’s league performances have dropped off in recent weeks but this was a display to be proud of, in front of their noisy 2,600 supporters.
City embarrassed David Moyes’ West Ham in the previous round and will feel they could have eliminated another top-flight opponent in the same FA Cup campaign for the first time since 1919-20.
Under their highly regarded head coach Liam Manning, they now turn their attention back to reviving their league form in the Championship.
Manning has a richly talented squad and Bell, arguably the best player on the pitch, did not deserve to leave the field on a low moment.