Kylian Mbappe and Presnel Kimpembe scored in that two-goal win, one which gives PSG a massive advantage heading into the second leg at the Parc des Princes
Cafu, who won Europe's top club competition with AC Milan in 2006-07, said PSG showed they were capable of getting to the decider without Neymar.
"All 16 teams that are competing in the last 16 of the Champions League have full potential to win, regardless of whether you lose your biggest star or not," he said on Sunday.
"Of course, Paris Saint-Germain will miss Neymar.
"He is a reference, but if you see the first game of Paris Saint-Germain away from home, with the achievement that they made, you see that PSG have a chance to reach the final.
"But, of course, with Neymar there is a further hope of victory and conquest."
Already 12 points clear in Ligue 1, PSG are bidding to win the Champions League for the first time.
PSG, who topped Saint Etienne 1-0 behind an Mbappe goal on Sunday, host Manchester United in the second leg on March 6.