Possession was roughly equal with Napoli creating five shots on goal to Madrid’s 19.
Giovanni Simeone put Napoli ahead in under nine minutes when he put away Giovanni Di Lorenzo’s square ball from close range, despite Andriy Lunin initially looking like he kept the ball from crossing the line.
It took Madrid just two minutes to reply as Rodrygo blasted the ball into the back of the net from just inside the box.
Jude Bellingham put Madrid ahead in the 22nd minute with a header from a wonderful ball into the box by David Alaba.
Zambo Anguissa brought Napoli level again two minutes after half time with a thumping shot from a tight angle.
Nicolas Paz Martinez restored Madrid’s advantage in the 84th minute with a long-range shot that should have been saved comfortably by Alex Meret. Instead, the ball went through his gloves.
Joselu made sure of the three points in added time when he ran to the back post to finish off the deft ball across goal by Bellingham.
Napoli need a point from their last game in order to guarantee progression to the next round.
