The Northumbrians dominated the game from start to finish with Jake Woods scoring a hat-trick of tries.
There were also two tries each for James Bird (who was making his 200th appearance for the club), Ben Gothorp and Hugh Todd, with Sam Eggleston, Simon Ord, Danny Clayton, Jonny Burn and Richie Elliott also getting in on the act.
Evan Moir kicked nine of his 14 conversion attempts.
Alnwick, who are sitting fourth in the table on 35 points, face league leaders Otley (49 points) in a key game at Greensfield on Saturday, kick-off 2.15pm.
Elsewhere, Alnwick 2nds won 17-7 away to Percy Park, whilst Alnwick 3rd went down 35-21 away to Houghton.
On Saturday, the 2nds are home to Morpeth Reivers in a friendly.