The Red Bulls got off to a flying start and led 36-12 at the break – Brandon Jackson opening the scoring after three minuets when the former Saracen caught a perfectly-judged cross-field kick from fellow debutant Zack Henry in the left corner.
A piercing run from Ollie Leatherbarrow almost delivered another early try, Ollie Fletcher saving one at the other end when the hooker scrambled back into his own 22 to win a jackal penalty from a Doncaster counter-attack.
But there was no stopping Telusa Veainu when the veteran full-back rolled back the years with a 70-metre interception try, the Tongan darting down the right wing as the Red Bulls tried to work a wrap-around play.
Former Newcastle fly-half Kieran Wilkinson’s missed conversion attempt kept the teams level at five apiece, and the Red Bulls went close to leading on the quarter mark when Oli Spencer was held up over the try-line following a James Elliott snipe.
It was the Knights who were next over, however, with another interception delivering their second score when Jordan Olowofela scooped up a loose ball and darted in.
The Red Bulls drew level when debutant Allan Ferrie supported a break from fellow back-rower Ollie Leatherbarrow to score down the left-hand side – Henry curling in a sublime conversion from wide out.
And it got even better on 27 minuets when another Newcastle man marked their debut with a score – Obi Ene powering in at the right corner following a break from Oscar Usher and a scoring pass from Sammy Arnold.
Harrison Obatoyinbo made an immediate impact after coming on from the bench, winning a jackal penalty near his own try-line and scoring his team’s fourth try of the night – the winger putting in a lovely stop-and-go to beat his man after being freed by slick hands along the line.
Ferrie followed up with his second as he broke from the 22 for a converted score down the left, and there was time for one more before the break when Fletcher burrowed over from a close-range tap penalty as former Newcastle centre Zach Kerr was sent to the sin bin.
That left the home side 36-12 up at the break, but the Knights emerged with gusto for the second half and scored a try in the left corner when replacement hooker Ben Sugars was driven over from a maul.
Alex Dolly slotted the touchline conversion, but Newcastle were soon back into their rhythm and had another try when Nathan Greenwood dotted down in heavy traffic near the right corner.
Sugars scored his second on the hour mark as Doncaster went over from a metre out – both sides turning to their benches in search of pre-season match minutes.
And it was one of those replacements who got the Red Bulls’ next try ten minutes from time, when South African wing Werner Kok won the race to a bouncing ball in the left corner.
Sugars completed his hat-trick when the Doncaster hooker was driven over from a maul down the right, but Newcastle had the last say when teenage winger Alfie Warwick marked his debut with a jinking score down the right.
Newcastle Red Bulls: 15 Oli Spencer, 14 Obi Ene, 13 Rhys Beeckmans, 12 Sammy Arnold, 11 Brandon Jackson, 10 Zack Henry, 9 James Elliott; 1 Micky Rewcastle, 2 Ollie Fletcher, 3 Murray McCallum, 4 Oscar Usher (captain), 5 Finn Baker, 6 Adam Scott, 7 Ollie Leatherbarrow, 8 Allan Ferrie.
Replacements: George Bolam, Charlie Evans, Fergus Callington, Ethan Grayson, Nathan Greenwood, Cameron Hutchison, Ollie Ashton, Werner Kok, Samson Adejimi, Elvis Kitenge-Fuki, James Harper, Rusi Tuima, Cam Jordan, Ben Douglas, Alfie Warwick, Harrison Obatoyinbo.
Scorers - Tries: Brandon Jackson, Allan Ferrie 2, Obi Ene, Harrison Obatoyinbo, Ollie Fletcher, Nathan Greenwood, Werner Kok, Alfie Warwick. Conversions: Zack Henry 3, Ethan Grayson.
Doncaster Knights: 15 Telusa Veainu, 14 Ryan Olowofela, 13 Semesa Rokoduguni, 12 Tololima Savaiinaea, 11 Penaia Tagutu, 10 Kieran Wilkinson, 9 Ollie Fox; 1 Logovi’i Mulipola 2 Nathan Langdon, 3 Jake Ellwood, 4 Adam Hopkinson, 5 Ben Glanville, 6 Bailey Ransom, 7 Max Allen-Paver, 8 Jasper McGuire,
Replacements: 16 Ben Sugars, 17 Connor Hancock, 18 Callum Hancock, 19 Aidan King, 20 Harry Yates, 21 Alex Dolly, 22 Aidan Cross, 23 Zach Kerr, 24 Jordan Olowofela, 25 Sam Kildunne.
Scorers - Tries: Telusa Veainu, Jordan Olowofela, Ben Sugars 3. Conversions: Kieran Wilkinson, Alex Dolly 2.
Referee: Henry Pearson. Attendance: 2,005.