Forest were trailing to efforts from Kei Kamara and a wonder goal from left-back George Friend, but he sent on strikers Matt Derbyshire and Darius Henderson and they both scored to rescue a point for the Reds against a Boro side who finished the game with 10 men following the injury-time dismissal of Emanuel Ledesma.
A delighted Davies said: "I said to the players at the end of the match that I was very proud of their performance, the effort, the commitment.
"The one thing we an say about this group of players is that they never give in, they have a fantastic energy and spirit about them and that's what makes me proud. It was a fantastic game of football and a fantastic performance from Forest.
"We thoroughly deserved to win the match and on another night we would have taken three points.
"They were 1-0 up with their only shot at goal in the first 45 minutes and then went 2-0 up through a wonder goal. But even at that point I was still confident we would get something from the game."
Referee Phil Dowd's performance was one of the main talking points after a frenetic encounter, with a series of bizarre decisions, but Davies refused to talk about the match officials, saying: "I will not comment on the referee's performance. I have no comment what to make whatsoever."
Opposite number Tony Mowbray, who was left nursing wounded pride after seeing his side throw away a two-goal lead, was more talkative about Dowd.
"I thought he got quite a bit wrong tonight," he said. "It's not an easy job, the modern-day referee. But he gets paid for making decisions and he made them."
Forest were awarded a first-half spot-kick for a foul by Rhys Williams on Raddy Majewski, but Andy Reid saw his kick saved by Jason Steele. Mowbray took umbrage at Dowd's decision.
"What I don't like officialdom at times is the over-dramatic nature of the decision," Mowbray added.
"He saw where the ball went - and I know Williams won the ball pretty cleanly - but the dramatic nature of him standing there for three, maybe four seconds, waiting and like a pointed dog when pointing to the spot in dramatic fashion. I don't think there's any need for it."
Mowbray also believed his side should have won a late penalty of their own when Marvin Emnes was brought down in the box, adding: "I'm sure Billy will be just as aggrieved as I am about the refereeing decisions. I cannot believe we were not given a penalty decision near the end - the lad has practically rugby-tackled around the waist and pulled him to the ground. It is unbelievable."
The Boro boss was, though, pleased with his side's display despite the end result.
He said: "They never really felt threatened. Yes they put a lot of balls in the box but (Jonathan) Woodgate and (Rhys) Williams headed a lot of balls out and stood out well, while we looked a threat on the break, highlighted by both of our goals.
"They nullified our passing game, but we stood up to the test pretty well."