The 16-year-old made a big impression for the Hoops.
Deila, who will leave Glasgow this summer after winning two Premiership titles, watched on from the dugout as his troops gave him a memorable parting gift.
Goals from Kieran Tierney, Tom Rogic and Mikael Lustig helped the Hoops into a commanding 3-0 half-time lead as they looked on course to bounce back from the disappointment at St Johnstone in midweek.
Stuart Armstrong, Manchester City loanee Patrick Roberts and Ryan Christie fattened the advantage by the hour mark, before 16-year-old Jack Aitchison, with his first touch, made it a magnificent seven for the magnificent Bhoys today.
In doing, Aitchison usurped David McLean as Celtic's youngest ever goalscorer, with McLean holding the record for 107 years. It was a memorable debut for the teenager, who also broke Mark Fotheringham's record of being the club's youngest ever senior player.
"It is up to us to build up our own legends."— Radical Celt (@RadicalCelt) May 15, 2016
Fantastic introduction to life at Celtic from Jack Aitchison. pic.twitter.com/xYvqya1H22
With Christie, Roberts and Aitchison in tow, Celtic certainly appear to have a bright future even without Deila.