The winger scored the third goal for the Hoops in the 3-0 win, which overturned the 1-0 deficit for the Scottish club from the first leg of the tie.
Brendan Rodgers' side will now face Kazakh side Astana in the next qualifying round.
“Tonight gave me a taste of what the Champions League would be like," said 19-year-old Roberts.
“It was incredible from the start with the unfurling of the flag and all the fans cheering and singing 'You'll never walk alone'.
“It was something special and I hope we can continue that and get through to the group stages."
Roberts also touched on his decision to not represent England U19 in the ongoing Euro Championships because of his club commitments.
He added: “Of course, they (England) are out there in Germany playing but I wanted to play in the Champions League, which was always my dream.
“I feel made for this stage. I've always believed in my ability and I've always wanted to play at the highest level.
“Wherever I'm playing, I'll do my best and give 100 per cent to reach my best level."
Wow! First taste of a European night at Celtic park was incredible! Onto the next round! #hailhailpic.twitter.com/DuYFlvW3q5
— Patrick Roberts (@patrick7roberts) July 20, 2016