Four of the goals arrived in the first 20 minutes and it took just six minutes for Lancaster to slide home Dean Parrett's low cross for the opener.
Palace replied within two minutes but it was soon 2-1 as Lancaster launched himself at Tom Carroll's deep corner and powered home his header from close range.
Zaine Francis-Angol set-up the third goal in the 20th minute, bursting down the left before feeding a through ball to Mason, who beat the offside trap and slotted into the corner.
Ryan Fredericks, who came back from injury to make his first appearance for the Under-18s at the weekend, was introduced as a second half substitute and took just five minutes to make his mark.
He was upended in the box and Mason made no mistake from the penalty spot for 4-1.
Mason was denied his hat-trick by the woodwork midway through the second half and Mirko Ranieri produced a couple of fine saves before Palace grabbed a late consolation.
Spurs XI - Ranieri; Waller-Lassen (Fredericks, 46), Khumalo, Nicholson, Francis-Angol; Parrett, Mason, Carroll, Luongo (Durojaiye, 70); Lancaster (Pritchard, 70), Dawkins.
I fully expect Khumalo to be in the 25 man squad this term and hopefully the South African will be ready to make his Premier League debut by the end of the month.