The big news in the buildup to this game was Neymar's absence through injury and Gerard Pique's return to the starting lineup after three months out of action.
A bright start to the game saw both sides fashion notable chances. Antoine Griezmann saw his shot saved by Keylor Navas from an acute angle, while Mauro Icardi's sliced shot was cleared off the line.
Barcelona were awarded a penalty when Layvin Kurzawa clumsily brought down Frenkie de Jong in the area. Lionel Messi stepped up to calmly dispatch the spot-kick and put the hosts one goal up in the 27th minute.
Their lead, however, lasted just five minutes as a brilliant team move ended with Kylian Mbappe dribbling across the Barcelona defence before firing past Marc-Andre ter Stegen.
The Barcelona goalkeeper produced several fine saves throughout the first half to ensure both sides went into the break level.
The second half saw the visitors up the ante with a host of chances created. However, they met an impenetrable obstacle in Ter Stegen.
Stunning reflexes were produced to deny Moise Kean, Kurzawa and Mauro Icardi. However, PSG took the lead in the 65th minute after a well-worked move down the right flank.
Alessandro Florenzi put in a delightful cross into the box, and Mbappe was on hand to convert after Gerard Pique's poor clearance had fallen into his path. There were complaints of offside from the Barcelona defenders but the goal was upheld after consultations with the VAR.
The visitors doubled their lead just five minutes later when Moise Kean rose highest to head home a set-piece by Leandro Paredes and put PSG 3-1 up.
Ronald Koeman made an immediate change, with Oscar Mingueza coming on for Sergino Dest. Three further changes were made by the Barcelona manager on the 78th-minute mark, but they failed to have any desired impact on the game.
Instead, it was the French champions who scored another goal in the 85th minute. A quick break saw Julian Draxler draw the Barcelona defenders to himself before teeing up Mbappe, who grabbed his hat-trick with an emphatic right-footed finish from 16 yards.
The victory gives PSG the advantage heading into the return leg in Paris in three weeks' time.
Here are five talking points from the fixture.
#5 Dominant PSG good value for their victory
PSG have flattered to deceive for most of the season and came into this clash sitting second in Ligue 1.
This is an unfamiliar position for the perennial league champions, and few would have given them any chance against Lionel Messi and co.
However, Barcelona themselves have been far from their dominant best, and this represented a perfect opportunity for the French champions to make their mark.
When the hosts raced into an early lead, it might have seemed like another Champions League away defeat was in the offing for PSG.
Despite the early setback, the visitors rallied and drew level within five minutes. From then on, it was practically one-way traffic, with Mauricio Pochettino's men asking all the questions.
They played their hosts off their own perch and would have had a more emphatic victory but for some fine goalkeeping by Marc-Andre ter Stegen.
In total, the Parc des Princes outfit had 16 shots, with nine of those hitting the target, compared to 12 and four for Barcelona.
Despite missing the services of key players like Neymar and Angel di Maria, PSG's utter dominance of Barcelona at Camp Nou sends a statement of intent to the rest of the continent about their readiness to claim top spot.
#4 Barcelona left needing a miracle to save their season
In the buildup to this clash, Ronald Koeman insisted that he could not see many teams better than his side on the continent.
The Dutch tactician maintained that his team were one of the most in-form teams in Europe and boasted that they could go toe-to-toe with any side on the continent.
In fairness to the 57-year-old, the Blaugrana came into this clash on the back of a 12-game unbeaten run, which is the second-longest unbeaten streak in Europe's top five leagues.
Each of those last seven games has ended in a victory for the Catalans but this excellent statistic does not tell the full story.
Barcelona currently find themselves off the pace in La Liga, with an eight-point deficit on Atletico Madrid - having played one more game. They also recently suffered a harrowing 2-0 defeat to Sevilla in the Copa del Rey first leg.
This leaves the UEFA Champions League as their only ostensible hope for a trophy this season.
In many ways, recent impressive victories have helped paper over the cracks at Barcelona. However, this dire display against PSG exposed how bad things currently are at Camp Nou.
Barring a miracle in the return fixture, it is highly likely that Barcelona will end the season trophyless for the second consecutive season.