Reynolds, touted as a possible replacement for the injured Nathan Cleary in the NSW side for game two of the State of Origin series, started and finished a movement that included an extraordinary flick pass from No.6 Ezra Mam.
The Broncos No.7 had an indifferent night up until the gamebreaker but showcased his class when the game was on the line at Suncorp Stadium on Saturday.
Newcastle's Kalyn Ponga and Dane Gagai were both sensational for the visitors after being overlooked by Queensland for the Origin series opener.
It was some statement by the duo in a display of absolute class.
Gagai set up two tries for blockbusting winger Dom Young and had a hand in another, while Ponga was his side's best.
The match had been billed as the battle between the new Queensland No.1, Reece Walsh, and the man he usurped for the crown, Ponga.
Both were brilliant in a ding-dong battle.
Knights skipper Ponga owned the first half with two line breaks and a sensational 60m try where he did it all himself. His last manoeuvre in the run was a left foot step that left Walsh grasping at air.
Walsh was dangerous enough in the first half but came alive in the second to set up winger Selwyn Cobbo for a try in the corner to give the hosts a 12-10 lead. Walsh then made a try-saving tackle on blockbusting winger Greg Marzhew.
Young showcased his speed and skill to race away and put Mat Croker over before he scored himself after Gagai genius. The Knights led 20-12 in the 58th minute and looked like the winners.
Walsh, not to be outdone, threw a cracking cutout pass to put Brendan Piakura over under the sticks in the 68th minute and the comeback was on.
Reynolds then came up with the magic that may yet result in him being given the task of helping resuscitate the Blues' Origin hopes.
The clash had so many heroes. Walsh had 13 tackle busts and ran for 214m. Ponga ran for 224m and had 10 tackle breaks in a showdown for the ages between two of the most exciting fullbacks of the modern era.
At the death Ponga hit Walsh under the ribs as both fullbacks came together in a match they both owned.
The crowd of 35,814 was the biggest for a Broncos-Knights game at Suncorp Stadium since 2008 in Wayne Bennett's farewell match in his first instalment as Brisbane coach.
