The manager was full in his praise of the young full-back, 20, who came in for his debut at St James' Park.
Kyle was named Man of the Match as goals from Dele Alli and Ben Davies secured a 2-0 win.
"He was fantastic," said Mauricio. "He was nominated Man of the Match - a better debut is impossible!
"He was very calm, played well. His decisions were perfect. He showed fantastic maturity and that’s good for the team. We’re all happy because he’s a great kid."
Below: Kyle in action at St James' Park
Mauricio then revealed that Kyle made a speech in the dressing room. "I pushed him a little, said ‘come on, say some words’ and he was fantastic, he said thank-you to everyone and the team showed how we are, the team is so tight, very good people, great professionals and it was fantastic to feel that after the game."
Moussa Sissoko started down the right in front of Kyle. "He did very well. It was his first game in the Premier League so congratulations to him. Everyone tried to help him and he deserved his chance. He showed he’s at the level to play and I hope he has a great career. He has the potential, he trains well every day and he was ready to start. He showed to everyone he’s a good player."
Goalscorer Dele added: "I feel like one of the older players now!
"He’s a fantastic player and he’s been working really hard in training. Like I’ve said before, we’re at a club with a manager where if you play well in training and work hard then you know you will get an opportunity to play in the Premier League.
"Kyle has done that and taken his opportunity and it was a great performance. There will be some competition now and I’m really happy for him."
Finally, Kyle's fellow full-back and goalscorer Ben Davies was equally impressed. "I thought Kyle was excellent and certainly deserves the plaudits he’s getting, including the Man of the Match award.
"Newcastle is not an easy place to come and to put in a performance like he did was credit to him and to all the Academy staff who have put everything in place for him to do as well as he did. It's something he's probablt dreamed about and to produce a performance like that, full credit to him."