"It was brilliant coming on and the reception I got from the fans just gives you confidence. The fans know I am a Hibs supporter myself and I think they are also delighted I am back.
"I had my ups and downs at Celtic, mostly downs, but it's great to be back playing football here."
Riordan also admitted he was excited at the attacking options amassed by his one-time team-mate Mixu Paatelainen, believing his new manager's philosophy on how the game should be played will have been forged by his own experience as a top-class striker.
He said: "He wants attacking football, that's what every striker wants. He wants the ball forward as quickly as possible, like our second goal when we broke so quickly. He will know as a former striker the frustration of being up there and not getting the ball quickly."