The Reds' perfect record in this season's Champions League ended on Wednesday evening as a result of Vedat Muriqi's 79th-minute winner in Turkiye.
Trey Nyoni had put the visitors 1-0 up midway through the first half, only for that opener to be quickly equalised by a deflected Mason Greenwood free-kick.
Isak restored his side's lead moments after coming on in the second period but Fenerbahce responded again through Archie Brown.
Read on for Isak's post-match interview with Liverpoolfc.com.
**On the game...**
It's never easy here but today I think we could and should get more out of the game. It's a bit sloppy that we had the lead twice and for us to then lose the game is not good enough. Obviously we're going to be disappointed from that.
**On the goals conceded...**
The atmosphere is really good and it's tough, of course. So, the one thing you can do to keep them quiet is score goals. So, it's a shame that we conceded quickly and we should capitalise on that. That's where we were lacking today.
**On scoring his first Champions League goal for Liverpool...**
I was happy with it at the time. I was hoping that it was going to lead to more. I'm always happy to score goals but today we lost, so it takes a bit from it.
**On back-to-back defeats...**
I think we've put ourselves in good positions, so that today if we lose this game it's not a chaos situation. We just need to get back to winning ways and if we win the next game, we are back to a really good position.