Jones chased through a bomb and showed great determination to plant the ball down after Knights captain Kalyn Ponga had set up two tries in a brilliant display.
The Dolphins lost winger Jack Bostock to a suspected ACL rupture in the first half at HBF Park.
Bostock scored four tries in his previous outing and has been touted as a NSW representative of the future.
His loss adds to season-ending injuries already for key forwards Tom Gilbert, Daniel Saifiti and Max Plath, along with the continued absence of prop Thomas Flegler with a shoulder nerve complaint since April last year.
Newcastle have struggled in attack in 2025 but had more strike with centre Bradman Best back from a hamstring injury and winger Dominic Young returned to the club after a mid-season transfer from Sydney Roosters.
Ponga, backing up from Queensland's win on Wednesday, played a true captain's knock. He got his hands on the ball when the game was on the line and set up two tries for Best with pinpoint grubbers.
Dolphins fullback Hamiso Tabuai-Fidow was also outstanding with the ball after his Maroons starring role.
Knights five-eighth Fletcher Sharpe swooped to score his 11th try of the season after a Jack Cogger bomb was dropped by Tabuai-Fidow.
Newcastle's kicking game was on song and they led 16-4 at one stage before the Dolphins hit back.
The dynamic Dolphins left edge was dangerous. Five-eighth Kodi Nikorima started and finished a move while new captain Isaiya Katoa put hole running specialist Connelly Lemuelu in with a precision pass.
The Knights lost Sharpe to an HIA and then centre Dane Gagai was sin-binned for a professional foul in the second half.
Katoa combined with versatile Kurt Donoghoe to put winger Jamayne Isaako over in the corner.
The Dolphins turned it on from their own tryline to take the lead with centre Herbie Farnworth igniting a move that was finished by Tabuai-Fidow.
Ponga laid on another try for Best with a pinpoint grubber to level it up at 20-all with 16 minutes to go before an enthralling finish that was capped by Jones' heroics.
The Dolphins had won their previous three matches and were gallant but the Knights were desperate and moved to 13th position with the win.
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