Forest headed into the Championship clash at the iPro Stadium on a run of four successive defeats in all competitions.
Many football followers expected Pearce’s team to lose, but the Nottingham-based outfit staged a dramatic comeback to register a 2-1 win.
Henri Lansbury headed Johnny Russell's corner into his own net in the 16th minute to put Derby ahead, but Britt Assombalonga equalised for the visitors in the 75th minute.
Then in injury time Osborn scored the winner for Forest when he shot home from 18 yards.
"All my mates are Derby fans,” Osborn told Sky Sports, according to BBC Sport. “I was getting messages from them last night saying: 'Don't score the winner.' The manager gave a team talk at the hotel before the game, and it was quite emotional.”
Pearce had come under pressure following Forest’s poor results of late, but the win against Derby will certainly increase his and his players’ confidence.
Although the visitors went behind at Derby, they did not lose heart and continued to ask questions of the home team’s defence.
After getting the equaliser, the Forest players stepped up their game and perhaps deservedly got the winner.
Forest fans will now hope that the team build on the win against one of the Championship’s best teams and push on for a playoff spot.