After applying a lot of attacking pressure from the off, Barcelona found the breakthrough via a penalty converted by Lionel Messi, after Luis Suarez was adjudged to have been tackled unfairly in the area by Jason Denayer.
Suarez then rounded Lyon goalkeeper Anthony Lopes to lay on a ideal pass for the unmarked Philippe Coutinho to nudge into an open net and double Barca's lead, although Lyon hauled themselves back into contention with a second-half strike from Lucas Tousart.
Barca coach Ernesto Valverde had warned his side of complacency after Paris St Germain and Real Madrid's surprise exits, and his words carried more weight after Atletico Madrid were knocked out by Juventus despite a 2-0 first leg win.
"All of the opponents are complicated", Messi added. "The referee can decide to give it or not".
Suarez added: "We were great in the first half". Let us know in the comments section below. We were able to recover the ball higher, posed problems and reduced the score.
"We have to concede they were better than us".
"When Messi is at such a level, he is nearly unstoppable". It is up to their little genius to make sure they make it through and show everyone who really is the best player in the world.
Lyon goalkeeper Anthony Lopes was hurt in a collision with Coutinho while the score was 1-0 and received lengthy treatment before continuing, only to then be substituted for Mathieu Gorgelin shortly after the Brazilian made it 2-0. "Finally, the doctor asked me to take him out so as not to take any chances".