The Eagles had twice trailed when Chilwell came on for his second debut, replacing Tyrick Mitchell who had already scored a double, to level the game at 2-2.
Within three minutes of his introduction, with his very touch, Chilwell latched on to a loose ball as Fulham failed to clear an attack, volleying home the decisive goal.
"To be fair, T [Mitchell] had scored two from left wing-back," he told Palace TV. "So it must have been a day for the left wing-backs.
"We spoke about the past few days, when I've been interviewed, but I'm buzzing to be back amongst the boys.
"I love being here, so to come back and score the winner in front of the Palace fans, it was great to see how buzzing the boys were. It's a great feeling."