Jonathan David canceled out Mohamed Salah's opener for Liverpool before substitute Harvey Elliott scored the winner midway through the second-half.
Genesio said afterwards: “I feel a bit sorry about the fact while we were disciplined in the first half, we were a bit timid. We weren’t really that keen on going on the attack and should have used the ball better. We didn’t move quickly enough or use overloads out wide.
“In the second half things were a little bit different and we tried to be more ambitious. We did equalise but didn’t make a good job defending the second goal.
“We may well have equalised again as we had some opportunities. Had we played in the first half as we did in the second half we might have done better.
“Hopefully this will help us grow and become more confident and make us aware of what we are able to do. We needed to go for it a bit more often and create more problems for Liverpool.”
Genesio added: “Of course we have a sense of frustration. When you lose you are always disappointed and frustrated. It’s a feeling which is mixed with pride as well. The display we put on, particularly in the second half when one man down, was something I’m very pleased with.
"But we’re frustrated particularly with the way we conceded the second goal. The real problem was that we lost the ball in midfield a lot and went a bit too wide too slowly. We know they are quick in transitions, not least of all Mohamed Salah, and the first goal they got us off balance but even before we lost the ball we could have done better in an attacking point of view.
“I have a few regrets but it shows the gap that still exists between us and one of the really top, top teams. There’s a reason they are top of both leagues they are in at the moment.
“They have seven wins out of seven in the Champions League so nobody should be surprised to see how they played this evening. They have highly-talented players and are extremely fast up front, which is important in modern football. They are very good one on one in the duels as well, and we saw the impact of that.”