The Ligue 1 champions weathered a first-half storm to emerge triumphant by two goals to nil in the opening encounter, since when their hosts have already experienced one dose of knockout dejection.
Match preview
Competing in the Champions League knockout rounds for just the second time under its current name, Real Sociedad - semi-finalists of the old European Cup in 1982-83 - had their moments in the first half at the Parc des Princes on Valentine's Day, but they were not feeling the love in front of goal.
Wasting a succession of promising chances in the opening period would unsurprisingly prove fatal in the French capital, where Kylian Mbappe broke the deadlock for Les Parisiens in the 58th minute, before Bradley Barcola surged past Hamari Traore and finished a slick solo run with a finish through Alex Remiro's legs at his near post.
A two-goal deficit is not insurmountable for Imanol Alguacil's troops, but history does not favour the men in blue and white, who lost 1-0 to PSG's Ligue 1 rivals Lyon in the first leg of their last-16 tie in 2003-04 - their only other knockout round appearance since 1992 - and suffered the same fate in the second leg.
Momentum is not on Real Sociedad's side either, as since following up their first-leg loss with a 2-1 triumph over Mallorca, Alguacil's men have been beaten in three straight matches, including a crushing Copa del Rey penalty-shootout loss to Los Piratas in the semi-finals.
A weakened team then went down 3-2 to faltering titans Sevilla in Saturday's La Liga fixture, meaning that Alguacil's out-of-sorts charges have just one victory to boast from their last nine games in all tournaments, and their alarming winless sequence at home stands at seven matches since they coincidentally beat Sevilla 2-1 in top-flight action in November.
Bidding to banish the last-16 curse which has haunted them in many a Champions League tournament, a PSG side still searching for their maiden top-level European honour need only avoid a catastrophic collapse at the Reale Arena to take another step towards that elusive crown.
While their upcoming hosts have recorded several blots on their notebook in 2024, the French champions head to Spain with an impressive 20-match unbeaten run to protect, although they have dropped points in their last two Ligue 1 fixtures with Rennes (0-0) and Monaco (0-0).
The gloves of Gianluigi Donnarumma were required on several occasions to keep the latter out on Friday night, but despite the watchable action on the pitch, the cameras would often pan to the stands, where Mbappe took his seat alongside his mother after a shock half-time substitution.
The Real Madrid-bound attacker will now experience a taste of the Spanish climate on Tuesday, where PSG will enter the second leg of a Champions League knockout tie ahead on aggregate for the 10th time, but they have only managed to advance on five of the previous nine such occasions.
Les Parisiens are also without a single clean sheet from 12 Champions League matches away to Spanish sides and were famously the victims of Barcelona's 2016-17 Remondata after a 4-0 first-leg success, but with just two goals shipped in their last six away games, the side led by Luis Enrique - the mastermind of that historic 6-1 mauling - should not suffer the same fate here.
Real Sociedad Champions League form:
W
W
W
D
D
L
Real Sociedad form (all competitions):
L
L
W
L
D
L
Paris Saint-Germain Champions League form:
L
W
L
D
D
W
Paris Saint-Germain form (all competitions):
W
W
W
W
D
D
Team News
Real Sociedad could not call upon the services of key defender Aritz Elustondo for the first leg - the 29-year-old was suspended on account of an accumulation of yellow cards - but he is now eligible to take to the pitch in Europe again.
Due to a toe injury, however, Elustondo was one of six players to sit out the loss to Sevilla, a list which also included Martin Merquelanz (knee), Alvaro Odriozola (ligament), Aihen Munoz (ACL), Carlos Fernandez (knee) and Ander Barrenetxea (back), although the latter might be fit to return alongside Elustondo on Tuesday.
Alguacil rotated heavily for the weekend's game with Sevilla with the second leg in mind, and by reverting to full strength in midweek, all of Mikel Merino, Robin Le Normand, Hamari Traore, Mikel Oyarzabal and Takefusa Kubo should return to the first XI.
As for the visitors, the departing Mbappe was taken off early for the second Ligue 1 game running on Friday night, and while he appeared to be walking with a very slight limp around the Stade Louis II track, Enrique revealed that his substitution was purely a tactical choice.
The ex-Barcelona boss reiterated that his team must "get used to" playing without the 25-year-old, but whether such cut-throat decisions from the Spaniard can continue until the end of the season is another question entirely, and it would be a shock to see Mbappe demoted to the bench for the second leg.
PSG should also be able to count on the return of Marquinhos, who was rested against Monaco due to a calf concern, but Milan Skriniar (ankle), Sergio Rico (head), Layvin Kurzawa (back), Danilo Pereira (thigh) and Presnel Kimpembe (Achilles) will not be involved.
In addition, Marco Asensio's race was run against Monaco with just 39 minutes on the board - the former Real Madrid man appeared to have hurt his thigh - so a spot has opened up for first-leg goalscorer Barcola to return to the side.
Real Sociedad possible starting lineup:
Remiro; Traore, Zubeldia, Le Normand, Galan; Mendez, Zubimendi, Merino; Kubo, Silva, Oyarzabal
Paris Saint-Germain possible starting lineup:
Donnarumma; Hakimi, Marquinhos, Hernandez, Mendes; Zaire-Emery, Ugarte, Vitinha; Dembele, Mbappe, Barcola
We say: Real Sociedad 1-2 Paris Saint-Germain (PSG win 4-1 on aggregate)
PSG will be under no illusions that they were fortunate to escape with a clean sheet from Friday's draw with Monaco, where Donnarumma proved himself as one of the world's best shot-stoppers, and second-leg collapses are nothing new for the French champions.