The 19-year-old led out the Magpies at Whitley Park as they extended their unbeaten run to seven matches, with first-half goals from Cal Roberts and Rosaire Longelo cancelling out Simon Power's opener for the Canaries.
After regular second-string skipper Owen Bailey did not feature in the squad, Watts was handed the armband for the first time at under-23 level, with the England youth international completely unaware of the sudden appointment before United's clash with their Norwich counterparts.
"It was great to be captain for the night," Watts told nufc.co.uk. "Owen has done a great job as captain this season and, when he wasn't named in the squad, it was a really proud moment for myself to be selected as skipper.
"I only found out just before the match and had absolutely no idea I'd be given the armband. I captained the under-18s for a few games last season and to captain the second string was a great feeling."
As well as deputising as captain, Watts, who can play in midfield as well as defence, featured alongside the returning Florian Lejeune, who was making his first appearance in a Newcastle shirt since sustaining a knee injury in pre-season.
Watts was pleased to learn from the experienced centre-back, as Lejeune made his comeback by completing the opening 45 minutes in front of a watching Rafa Benítez.
Watts added: "It was fantastic to play alongside Florian. He's a great player and has had a tough injury but he has worked hard and seems ready to play again.
"He is a pro who has played first-team football so it was great to see what the level is like and be able to base my performance on him along with contributing things he does well and adding them into my own game as well."