PSG sit on nine points in the group alongside Manchester United and RB Leipzig, whereas Istanbul are the only team not in contention for a top-two finish and have nothing but pride to play for here.
Something has to give in United's crunch match with Leipzig on Tuesday, so as long as PSG record an expected victory over Istanbul Basaksehir, their top-two finish and place in the last 16 will be confirmed.
However, that will do little to ease the growing pressure on Thomas Tuchel, with the Parisiens faithful becoming restless as their side search for a maiden Champions League crown.
Last week's dramatic victory at Old Trafford did wonders for PSG's cause, with an exceptional performance from Neymar inspiring Tuchel's side to a 3-1 win against United, who were very fortunate to still have 11 men on the field heading into half time following Fred's altercation with Leandro Paredes.
Nevertheless, Neymar bagged a brace while Marquinhos also prodded home in Manchester - with Fred eventually given his marching orders after the latter's goal - but Man United still lead the way owing to their superior head-to-head goal difference between the three top teams in Group H.
A Champions League last 16 without one of United, PSG or Leipzig seems incomprehensible in 2020, but the Ligue 1 champions' destiny is still in their own hands and no matter what happens at the Red Bull Arena, PSG will advance should they overcome Istanbul on Tuesday.
Tuchel's team will be feeling as confident as ever heading into this one after they recorded a second consecutive 3-1 win away from home, this time putting fellow high-flyers Montpellier to the sword in Ligue 1 thanks to goals from Colin Dagba, Moise Kean and Kylian Mbappe.
In contrast, Istanbul are already resigned to a fourth-placed finish in this daunting group, although the Turkish side were never expected to challenge one of the three European powerhouses for a knockout berth.
That memorable victory over Manchester United will live long in the memories of Okan Buruk's men, but Istanbul have lost every other game in the group and will simply be playing for pride at the home of the Ligue 1 champions.
Nevertheless, the Turkish outfit gave it a real good go against Leipzig, with Irfan Kahveci netting a terrific hat-trick against the Bundesliga giants, but Alexander Sorloth netted an injury-time winner for Leipzig in a 4-3 victory for Julian Nagelsmann's men last month.
Istanbul's next fixture was a much quieter affair by comparison, with Buruk's men playing out a 1-1 draw with Yeni Malatyaspor - a result which leaves them winless in their last six games in all competitions.
PSG made the long journey to Turkey count when they faced off against Istanbul Basaksehir back in October, with Kean netting both goals in a routine 2-0 win for the Ligue 1 champions in matchweek two.
Paris Saint-Germain Champions League form: LWLWW
Paris Saint-Germain form (all competitions): WLWDWW
Istanbul Basaksehir Champions League form: LLWLL
Istanbul Basaksehir form (all competitions): LLLDLD
PSG made wholesale changes for their trip to Montpellier, but Tuchel will certainly revert to his regular 4-3-3 and welcome several first-team stars back to the fold on Tuesday.
Mbappe was named on the bench and Neymar did not feature at all on Saturday, but both men are sure to come back for this one, as will Marco Verratti, who was also given the night off against La Paillade.
As for the visitors, Martin Skrtel is banned for this one after picking up his third booking of the group stage in the defeat to Leipzig.
With Alexandru Epureanu out with a muscular problem, and Ravil Tagir not eligible, Mahmut Tekdemir may be forced to deputise in the heart of defence alongside Ponck, who scored an own goal at the weekend.
Edin Visca was forced to miss the draw with Yeni Malatyaspor after being forced off against Leipzig, but the 30-year-old is expected to be fine for the trip to the French capital.
Paris Saint-Germain possible starting lineup:
Navas; Florenzi, Marquinhos, Kimpembe, Diallo; Pereira, Paredes, Verratti; Di Maria, Mbappe, Neymar
Istanbul Basaksehir possible starting lineup:
Gunok; Rafael, Ponck, Tekdemir, Kaldirim; Kahveci, Ozcan; Visca, Giuliano, Chadli; Ba
We say: Paris Saint-Germain 3-0 Istanbul Basaksehir
PSG cannot afford to beat around the bush or try and score the perfect goal in this game - ensuring that his side come away with all three points is of paramount importance to Tuchel here. Even with a weakened team, PSG still trounced Montpellier on their own turf at the weekend, and we expect the Ligue 1 champions to book their place in the last 16 with a resounding victory over an out-of-sorts Istanbul Basaksehir side on Tuesday.