The live television cameras were rolling and there was a large crowd in attendance at Stevenage - and what a game they witnessed!
Tammy Abraham's opener for Chelsea was cancelled out by Shaq Coulthirst with a fine looping header into the top corner, but the Blues hit straight back through Fikayo Tomori to take a 2-1 lead in at half-time.
Kasey Palmer increased the visitors' advantage, Coulthirst got one back, Jay DaSilva made it 4-2 before a late brace from Andros Townsend - the first from the penalty spot - restored parity.
However, Chelsea found the telling strike when Jake Clarke-Salter fired home in the fourth minute of stoppage time.
Spurs U21s: Glover, Amos, Georgiou, Lesniak (Sonupe 58), Veljkovic (c), Carter-Vickers, Townsend, Winks, Coulthirst, Walkes (J Pritchard 74), Miller (Goddard 83). Substitute (not used): Voss (GK).
Chelsea U21s: Collins, Dabo, Tomori, Clarke-Salter, DaSilva, Colkett (c), Mitchell, Ali (Kiwomya 46), Abraham, Palmer, Musonda. Substitutes (not used): Wright, Quintero, Colley, Russell (GK).