The forward delivered the U18 Premier League North clash’s decisive moment early in the second half for Simon Wiles’ charges.
The home side had mounted some early pressure with a succession of shots, though only one drew a save from DJ Bernard.
Liverpool began to claim a majority of possession as the half wore on but were unable to translate it, or several corner kicks, into clear chances.
And stalemate continued to half-time as neither goalkeeper was unduly troubled at the Magpies’ academy base.
Bernard thwarted Isaac Moran’s close-range header as Newcastle again made a strong start to a half.
But the Reds made their dominance of the ball count nine minutes into the second period with a fine goal.
Erik Farkas slipped away from a marker deep on the right flank and passed to Finn Inglethorpe, who in turn fed Sonni-Lambie into the area.
The latter continued his prolific form this season by chopping inside Thomas Old and dispatching a curled finish off his left foot.
Bernard produced an important intervention to deny Michael Mills from a good opportunity for the hosts.
Liverpool crafted several openings as they sought a second goal, looking the likelier of the two teams to net.
And Sonni-Lambie will feel he should have doubled their lead having been set up by Farkas for a one-on-one 12 yards out.
This time, he fired his shot well over the bar, but his earlier effort proved enough as it remained 1-0 to the Reds at the final whistle.
Team
Liverpool: Bernard, Hickman, Ayman, Esdaille, Clarke, Murray-Holme, Abe (O’Connor, 60), Upton, Inglethorpe, Farkas, Sonni-Lambie.
Unused subs: Conde, M. Wright, Powney Wain, Lee Forrester.
Next up
Wiles’ team are back in U18 Premier League North action next Saturday (January 24), hosting Burnley.
Kick-off at the Kirkby Academy will be 11am GMT.
