Palmer, 18, played for almost the full 90 minutes at right-back in the 2-0 success.
"Since I've been here Ash has been surperb around the place. I didn't know much about him before I came in but in pre-season I just flung him in at right back and realised I've got a player on my hands," Knill told the club's official website.
"He's really a centre half but we thought we'd stick him at right back to sort his feet out and give him some more confidence on the ball. We always knew that Ash would play when this fixture came out so it's just been a case of where we eventually played him."
Aron Wint also made his competitive Iron debut, who replaced Bobby Grant after 85 minutes.
"I'm delighted to get Aron on the pitch as well. The young guys have done really well in training and it's a great reward for them," added Knill