Thomas Tuchel's men gave themselves the best chance possible of advancing with a 3-1 win at Manchester United last week, with the Ligue 1 champions now level on points with United and RB Leipzig, who lock horns in the other clash in Group H this week.
PSG made several changes for their trip to Montpellier in the league on Saturday, but the Parisiens ran out 3-1 winners at the Stade de la Mosson, with Colin Dagba, Moise Kean and Kylian Mbappe all scoring on the road against La Paillade.
Here, Sports Mole looks at how PSG could line up for their crunch match with Istanbul Basaksehir on Tuesday evening.
In an unfamiliar move, Tuchel opted to start with five defenders against Montpellier, but it was a tactic that ultimately paid dividends as PSG recorded an important win at the Stade de la Mosson.
However, with the Parisiens needing to stamp their authority on Istanbul Basaksehir this week, Tuchel will no doubt make several changes and revert to his favoured 4-3-3 system once again.
Dagba's first goal for the club is unlikely to see him keep his spot at right-back over Alessandro Florenzi, while Marquinhos and Presnel Kimpembe are set to return in the heart of defence after being given the night off against Montpellier.
Abdou Diallo garnered plenty of praise for his performance on the left-hand side of PSG's defence at Old Trafford, and the 24-year-old could find himself deployed as a full-back again here, with Mitchel Bakker and Layvin Kurzawa both starting PSG's weekend victory alongside Diallo.
Timothee Pembele was handed another start by Tuchel after his horror debut against Bordeaux - which saw the 18-year-old score an own goal inside the first 10 minutes - but Pembele will be dropped here as Tuchel switches back to his tried-and-tested formation.
The PSG manager could overhaul his midfield by recalling Danilo Pereira, Leandro Paredes and Marco Verratti - the latter of whom missed out entirely at the weekend - in place of Idrissa Gueye, Ander Herrera and Rafinha.
As we move further forward, Moise Kean's resurgence in the French capital continued with yet another goal for the Ligue 1 champions against Montpellier - his seventh for the club - but the youngster is likely to make way as PSG's formidable front three look to produce the goods against Istanbul Basaksehir.
Kylian Mbappe came off the bench to net late on at the Stade de la Mosson and hit double figures for the league season, and the 21-year-old is expected to spearhead the Parisiens attack on Tuesday.
Out wide, Angel Di Maria should retain his spot in the team after playing the full 90 against Montpellier, while Neymar - who was the star of the show in PSG's victory at Old Trafford - will complete Tuchel's lineup in this must-win game.