Argentina winger Angel Di Maria scored twice as Paris Saint Germain demolished Barcelona to leave the Luis Enrique side in danger of failing to reach the UEFA Champions League quarter - final for the first time in decagon.
Unai Emery side dominated this last - 16 first - leg tie all over and took the lead through Di Maria's unstoppable free - kick.
Germany winger Julian Draxler netted a second with an angled drive before Di Maria curled an exertion into a top - corner.
Uruguay striker Edinson Cavani then sealed a famous victory with a strongful fourth.
A colorless Barcelona with Lionel Messi, Neymar and Luis Suarez largely innominate did not generate an effort of note untill seven minutes before the end when Barca defender Samuel Umtiti headed to the post.
The last leaves Spanish side Barcelona with an invincible task to visit in the competition when they host PSG in the return leg on March at Camp Nou.
No team has trained to flip over a four-goal first - leg default in the UEFA Champions League.
Luis Enrique side cruised into the knock out stage by topping Group C, they won 5 matches out of 6 matches.