Saracens Mark Bartholomuesz looked to have sealed the win for his team with a last-minute drop-goal, but Falcons captain Jonny Wilkinson snapped over one of his own to steal victory from under the visiting team inside injury-time.
Wilkinson had had a mixed game up to that point, with the Saracens pack in complete control, he had been starved on any quality possession.
The first half started at a ferocious pace, with both sides eager to move the ball out of the contact.
Saracens opened the scoring after four minutes when Newcastle coughed up possession 30 metres out from their own line.
The ball was worked out to Thomas Castaignede who timed his run perfectly. He cut inside, wrong-footing his opposite man Dave Walder, and slid in under the posts. The French star added the extras with the conversion.
Falcons hit back immediately when Epi Taione made a thunderous break through the middle.
He slipped short of Castaignede and his head smashed straight into the full-back's knee.
Inevitably Castaignede came off worse and he was helped off the pitch four minutes later.
However, Taione's break had created space out wide for the Falcons, and Matthew Tait exploited it with a clever kick ahead which he then gathered and touched down in the right corner. Wilkinson converted from wide out.
Sadly that was the end of the quality rugby for the rest off the half. The only other points coming from Castaignede's replacement Robbie Kydd who slotted a 40-metre penalty.
Sarries spurned chance after chance, and despite their glut of possession, they were unable to produce the critical blow.
Even with a one man advantage – after Taione was sin-binned on 35 minutes for persistent infringements – Saracens were unable to push home.
The hosts would have been delighted to go into the break just three points behind at 10-7. And Wilkinson levelled the scores just after the restart with a penalty.
The pattern of the first half continued with Saracens applying the pressure but failing to put points on the board, despite having further numerical advantage after Mike McCarthy was sin-binned for aiming a slap at Ben Broster.
Newcastle scored a breakaway on 53-minutes when they stole the ball five metres short of their own line and Tait kicked ahead.
Referee Tony Spreadbury allowed play to continue despite an early tackle by Tait and Michael Stephenson out-paced the defence to gather his own kick and score. Wilkinson again converted.
Sarries hit back with a well worked try for Matt Cairns. Kydd's conversion levelled the scores at 17-17 after 56 minutes.
Falcons came close on 66 minutes, but Tait was unable to ground the after a flowing Falcons back move.
Saracens looked to have made Newcastle pay when Bartholomeusz calmly slotted the 30-metre drop-goal with time almost up on the clock.
But Wilkinson was not to be outdone and he replied with the last kick off the game to level matters at 20-20.
For Newcastle:Tries: Tait, StephensonCons: Wilkinson 2Pen: WilkinsonDG: Wilkinson
For Saracens:Tries: Castaignede, CairnsCon: Castaignede, KyddPen: KyddDG: Bartholomeusz