Ousmane Dembele's double saw PSG win 2-0 on the night and the quarterfinal tie 4-0 on aggregate.
Afterwards, Slot insisted: "I think we made a lot of progression compared to last week. I have to give a lot of credit to the players, how hard they worked. I have to give a lot of credit to our fans, how they helped us tonight to execute our game plan.
"And that means if we have a high press, it's so helpful if there are fans behind you to keep on pushing you. That's what they did. Unfortunately it's one of the many examples of this season where we weren't able to score from the many chances we had.
"Again, we were so underperforming in terms of xG and that is just an ongoing thing with us throughout the whole season. And add to that, it seems to be a bad injury (to Hugo Ekitike) – we don't know (for) sure yet. Add to that another intervention of the VAR, which went not in our favour and that's also not for the first time this season.
"Then of course we are very disappointed because I think there were parts in the second half where you could just feel, 'If we can score now this is going to become a special night.'
"But the future looks very bright for this team, for this club because we've shown that we can compete with the champions of Europe in our stadium, to be the dominant team – not many teams can be dominant against Paris Saint-Germain and generate so many chances as we did. But yeah, chances is one thing, scoring is a second."
Isak starting
On his decision to start Alexander Isak - his first since suffering a double leg fracture before Christmas - Slot insists the gamble was worth it.
He also said,"I said before the game, if you go to extra-time and he plays in the second half and plays 45 minutes there is only two minutes in between before extra-time comes up for half an hour and I don't think that was realistic. But to play him 45 and let's see at half-time how he feels to add five to 10 minutes to that, that was a possibility for today.
"But because we already had to make the first substitution in the first half, I didn't want to make the second substitution five or 10 minutes after half-time – that's why I took him off at half-time.
"He was twice close to a goal and that's why you play a striker of his level – there was one header from a set-piece and there was one great run in behind (Willian) Pacho, which he was really close to scoring but eventually was offside. It is good to see and to have him back.
"I think he was ready and if I thought he wasn't ready then I wouldn't have played him. I think if you compare us today to last week, I think it is fair to say he was completely ready to play, otherwise you can't play the first half as we did, although the second half was even better."