Real are top of Group C on six points from two games, three ahead Napoli and Braga.
While there were frazzled nerves at the end, Real started the game strongly with the Vinicius and Bellingham creating all kinds of trouble for the hosts' defence.
However, veteran midfielder Luka Modric climbed off the bench to liven up Real Madrid late in the game.
He first put it on a plate for Bellingham, who missed a sitter from close range in the 75th minute.
Reporting by Fernando Kallas in Madrid Editing by Toby DavisOur Standards: The Thomson Reuters Trust Principles.
Persons:
Alex Meret, Vinicius Jr, Jude Bellingham, Leo, Piotr Zielinski, Federico Valverde cannoned, Real, Vinicius, Bellingham, Kepa Arrizabalaga, Giovanni Di Lorenzo, Nacho, Carlo Ancelotti, vociferously, Clement Turpin, It's, Ancelotti, Diego, Arrizabalaga, Victor Osimhen's, Luka Modric, Valverde, Modric, Fernando Kallas, Toby Davis
Organizations:
Real Madrid, Napoli, Champions League Group, Real, Braga, Union, Movistar, Diego Maradona, Thomson
Locations:
NAPLES, Italy, Real, Union Berlin, Bellingham, Vinicius, Madrid