Forest fell 2-0 down when Gabriele Angella scored his second goal of the game two minutes after half time at the City Ground.
Davies told Forest's official website: "First half the energy from back to front was not good enough. We struggled to create any clear-cut chances and we defended the set pieces very poorly.
"In the second half we were exceptional. The lads showed an outstanding attitude and great bottle to deliver three fantastic points.
"The three substitutes were magnificent tonight. Their energy and work rate was reflected in the goals they scored and I'm really pleased for the three of them."
Forest, who are currently fifth in the Championship table, are now unbeaten in 12 matches since November.