Chelsea took the lead through Ike Ugbo with just 30 seconds gone and doubled their advantage through Martell Tyler-Crossdale in the second period.
However, Arsenal showed excellent resilience to come back, with Nketiah, who trained with the first-team yesterday, reducing the deficit following good work from Willock.
Willock then found the net himself from the penalty spot to salvage a point for Arsenal.
Arse all: Virginia; Osei-Tutu, Olowu, Pileas, T. Bola; DaSilva, Dragomir; Smith-Rowe, J. Willock, Malen; Nketiah.
Info via ChelseaYouth