As someone else used to say there was a buzz about the place when Forrest got on the ball with his blistering pace matched by the accuracy of his crosses from the wide areas.
As early as the second minute he posted notice of his intentions with a great front post cross that Marco Fortune sent into the side net.
Eighty minutes later he was still going strong supplying a perfect cross for Gary Hooper to score on his Celtic debut.
There was no shortage of pace down the right flank as Forrest and Cha Du-Ri combined with the Lyon defence struggling to cope in the humidity of the Emirates Stadium.
Forrest made a scoring debut for the first team against Motherwell last season and is hoping to carry pre-season form into the new term.
“The pre-season has been great, I’ve enjoyed every game,” he admitted. “ I played in all four games in America and Canada- even getting on the park against Braga was a good experience.
“Playing against Manchester United was fantastic, I’ve grown up watching them every week on telly then all of a sudden I was up against them.
“For half an hour I couldn’t believe it but as the game went on I settled into it. To be playing against Ryan Giggs and Paul Scholes was amazing, that’s what you are in football for.
“It wasn’t intimidating, this is what you want to do as a player, you want to be up against the best and test yourself.”
The likely departure of Aiden McGeady brings into focus youth development at the club with Stephen McManus the last player to come through the ranks and establish himself in the first team.
Every club is working towards developing their own young players but at Celtic the standards are higher than elsewhere.
Competing with million pound signings and internationalists isn’t easy but Neil Lennon has identified Forrest as first team material.
Lennon and Forrest worked together last season in the development squad with the teenager determined to justify his place in the new boss’s first team plans.
Forrest added: “Towards the end of last season Neil Lennon told me that he was looking to get me involved, he’s stuck by his word and I hope that it continues.
“The manager has told me that I’m a first team player but I have to earn it, I can’t ease up. I have to impress every day in training to earn a place.
“Every club likes to bring through their own players and there are a lot of good players coming through at the club.
“James Keatings, Richie Towell and the twins (Twardzik) are doing well and it would be great to see more of them coming into the side.
“It was nice to be announced as man-of-the-match but there was five minutes left to play and getting an equaliser was more important.
“Cha is great to play alongside, he’s got a great engine and can get up and down the park all day- he looks like a good signing.”