The Czech champions equalled the record for the most goals conceded in the group phase of the competition (24).
His much-changed outfit were ahead inside six minutes, when Marcos Alonso was first to respond to Ansu Fati’s shot being parried onto the line, slamming home his first ever Barcelona goal.
Plzeň’s failure to take those chances would be punished on the stroke of HT, as Raphinha’s incisive lofted ball allowed Jordi Alba to nod across goal, where Ferran Torres was waiting to slam home from close range.
After being brought down by debutant Pablo Torre inside the area, Chorý picked himself up and dispatched from 12 yards to reduce the arrears.
Plzeň refused to lie down though, wanting to avoid the unenviable record of losing all six group stage games.
They were taking advantage of the Blaugrana’s inability to defend high balls into the area, with the six-foot-six striker Chorý only too happy to capitalise and nod home his second of the night.
Torre atoned for conceding the penalty with an emphatic finish to net his first goal for the club, ensuring Barcelona avoided losing four consecutive UCL away games for the first time this century.