Anthony Gordon scored his fourth Champions League goal of the season, opening the scoring for Newcastle in the 32nd minute.
Substitute Harvey Barnes netted an exquisite double in the second half, with his first goal coming from a remarkable long throw by goalkeeper Nick Pope.
Gordon's impressive performance earned praise from manager Eddie Howe and an admission from Jose Mourinho that he was a 'problem'.
The win lays a strong foundation for Newcastle's qualification from the group stages and boosts the team's confidence, with Howe noting a return of attacking prowess.