Afobe scored a late second to wrap up all three points against Wolves' Midlands rivals, with Molineux already in party mood after promotion was secured thanks to Brentford's draw at Fulham on Saturday.
The goal was Afobe's fifth since returning to the club on-loan on January.
He said: "To come on and score in this environment is special for me, personally.
"When I came back to the club, I obviously knew that I had a point to prove. It's been two years since I was last here and the team has moved on and got better, with all due respect, so I had to up my game as well.
"I wasn't going to rest on my laurels. I think I've contributed - I've got five goals now, but there are still three games to play - I want more and the team wants more."
Afobe watched on with the rest of the squad as promotion was sealed without Wolves kicking a ball on Saturday, but he says that the attitude within Nuno's squad meant that focus never wavered from claiming another three points against Blues.
"There were obviously celebrations last night, but we were focused on the game today," he added. They're fighting to stay up - even when they went down to ten men, it was still a tough Midlands derby. We knew that we had to play properly, and we did that, and picked up another clean sheet and another two goals.
"It's unbelievable. Words can't describe how I feel right now. How the squad feels, how the fans feel, how the staff feel - it's unbelievable to be part of this."