Mbappe came off the bench and scored three goals in a devastating performance as PSG routed Club Brugge 5-0 on Tuesday.
The PSG sensation became the youngest player to score 15 Champions League goals aged 20 years, 306 days, eclipsing Barcelona superstar Lionel Messi – who was 21 years, 288 days.
Silva was thoroughly impressed Mbappe, who has quickly put recent injury issues behind him.
"He is well present, he is ready, he has gifts, I can't tell you more because he is an incredible player," Silva said.
"I'm very happy for him, for the team, for the way we played today. In the first half it was very difficult, we knew it, but in the second half we were much more effective.
"We had chances, we scored. Especially Kylian, this player is magnificent."
PSG were ruthless in Brugge, where the Ligue 1 holders made it three wins from three games in Group A as they closed in on the knockout round.
Mauro Icardi opened the scoring in the seventh minute, before Mbappe doubled the lead within nine minutes of his second-half introduction.
Mbappe supplied the assists for Icardi's second of the match in the 63rd minute, while the former took centre stage with another two goals to take home the match ball.
"We won a very tough game," PSG head coach Thomas Tuchel said. "Very complicated. The result is exceptional.
"It's never easy to win against Brugges in Brugges. In the Champions League outside it's never easy. We scored five goals, it's really exceptional. It's a big step forward for the qualification [for the last 16]."
PSG have now won their past five games in all competitions, conceding once and scoring 15 goals in the process since a 2-0 loss to Reims.
Tuchel's side next face Marseille in Ligue 1 on Sunday with PSG already five points clear at the domestic summit.
The Parisians also look set to comfortably top Group A in the Champions League with Real Madrid trailing PSG by five points.