The 20-year-old rose above a static Georgian defence to head home Joe Cole's corner for England's opener at Middlesbrough. It was his first goal having played 49 times for Spurs and winning his seventh cap at this level.
Young looked as surprised as anyone and admitted: "I certainly didn't have any celebration planned! I saw the corner going above everyone else and just attacked it. To be honest though the goalkeeper should have saved it."
England went on to win 6-1 in a one-sided game with Arsenal's Ashley Cole, Everton's Francis Jeffers, David Dunn of Blackburn, Manchester United's Jonathan Greening and Watford's Tommy Smith on target.
Young only played the first half as boss Howard Wilkinson made 10 substitutions in total. "It would have been nice to have played more but I was delighted to be out there," added Young. "When I'm not playing for the first team I have to rely on the reserves so this represents a higher standard of football.
"I think our qualifying campaign for the European Championships starts in October so hopefully I'll be involved in that one. Until then I just want to play as many games as I can at Spurs. That's my main aim."
England U21s: Robinson, Newton (Stockdale, 80), Young (Carlisle 45), Bramble (Prutton 45), A Cole (Thirlwell 73), Greening (Chadwick 63), Carrick (Hargreaves 63), J Cole (Parker 73), Dunn (Wright 45), Vassel (Smith 73), Jeffers (Campbell 63).
Luke Young broke his goalscoring duck as England Under-21s hit Georgia for six in Thursday night's friendly.