Now chasing the game, in order to keep their title push alive, the young Eagles did not relent. A Chelsea corner was cleared into the path of Kai-Reece Adams-Collman who led the breakaway to find Brownlie - the Australian’s shot was just across the face of goal.
Joseph Wheeler-Henry nearly added a second for the hosts in first-half stoppage time, though Marcus Hill was equal to it in the Palace goal.
After the break, it was all Palace. Dean Benamar - pushing forward from left wing-back in search of the equaliser - met a Drakes-Thomas cross at the far post with his head, though it was scrambled behind by Sands and the Chelsea defence.
Moments later, an excellent over-the-top Rabona pass from Williams saw Adams-Collman in behind, however the midfielder’s effort was just past the ‘keeper and bar.
Chelsea’s best attempt of the half was smothered by Hill near the hour-mark, as he denied Mahdi Nicoll-Jazuli who was through on goal. Palace meanwhile continued to dominate the ball and muster half-chances as the half went on.
Casey fired over the bar, after a great ball in from Jasper Judd was spilled by Sands, while a Williams free-kick cannoned back off the bar into the path of substitute Jerome Osei to convert - although he was ruled to be offside.
As the game converged towards stoppage time, Palace continued to press for an equaliser. Williams’ driven cross across the face of goal was met by a stooping Benamar, though the left-back’s effort was wide.
Donte Martin, on as a late substitute, had a golden chance to draw Palace level with just two minutes of normal time remaining. The young forward got on the end of an inch-perfect Adams-Collman ball into the box, only for Sands to smother his effort from close range.
Ultimately, it wasn’t to be for the young Eagles as they fell to the narrowest of defeats. The result means the side remain in top spot in the U18 Premier League South, one point clear of Southampton and two clear of Chelsea, though both the Saints and the Blues have two games in hand.
Chelsea: Sands (GK), Wheeler-Henry, Subuloye, Diakite, Nutter, Harrison, Gordon (Runham, 68), Nicoll-Jazuli (Idrissi, 78), Ezenwata, Walsh (Waite, 90+1), McGlinchey (Kavuma-McQueen, 68).
Sub not used: Grimwade.
Palace: Hill, Judd, Benamar, Danaher (Okoli, 75), Somade, Fasida, Drakes-Thomas, Adams-Collman, Casey (Martin, 83), Williams, Brownlie (Osei, HT).
Subs not used: Whyte, Whitworth (GK).