"When I scored, I didn't know what to do. I dropped to my knees. I was crying."
The 22-year-old, who has been at Chelsea since he was eight, made a surprise debut in Wednesday's Uefa Super Cup win over Villarreal, having impressed Thomas Tuchel in pre-season.
And he went one better on Saturday on his Premier League debut. The centre-back picked the ball up in space, drove forward and hammered in a screamer from 25 yards which clipped the inside of the post on the way in, the third goal in a 3-0 win over Crystal Palace.