After PSG conceded the first goal, they immediately began to play nervously, there was more aggression, and this never leads to a good result, and as a result - a red card. I think that PSG has very few chances of reaching the final.
i remember some game, like Bayern Monaco vs Manchester United or
Manchester United vs Juventus FC
one team lead the game all the match, but at end

lose the match!
in last games of big competition, nothing is sure.. PSG is not experienced but is strong (for this reason is nervous)
for me have chance to pass this round