We obviously underestimated PSG in that match because we forgot that they eliminated the big boys of the English Premiership which is Liverpool and were notorious against Aston Villa. If they could win two strong sides from the English Premiership, I don't think winning a third one will be rocket science. Nevertheless, Arsenal won them once in this year's tournament, and that makes the dynamics a little different. So both of them now have won each other which means the next match could end in a draw.
After beating Real Madrid things were good favourable for Gunners, and they were feeling now they are champions of this season but PSG and Luis Enrique bring them back on earth now they have to give their best in second leg game if they are looking for spot into final but for me PSG is having better chance. They are playing with game by game strategy which is helping them for having good results and better understanding of opponents which is currently the most important thing for any team in this competition I have good difference of strategy between Arteta and Luis Enrique second one is more experienced and have better mindset about big events.
Second leg game is going to be challenging for both teams because Arsenal can fight back but still it's going to be not easy for them at Paris while all will be favourable for PSG.