Celtic supporters set off pyrotechnics devices in a massive display ahead of the match against Dundee.
Fans in the away end at Dens Park set off flares as the teams emerged from the tunnel for the Scottish Premiership contest.
Smoke could be seen blowing across the pitch but there was no impact to the scheduled kick-off time.
Celtic are currently under investigation by the SPFL over the use of pyro devices at matches with the Premier Sports semi-final and final cited by the governing body.
Kick-off was delayed in both matches with disciplinary proceedings underway over both incidents.
Rangers also face SPFL action over the use of pyrotechnics with Motherwell also being probed after fans used pyro devices at Hampden.
A Celtic statement after the SPFL confirmed disciplinary proceedings read: "Celtic Football Club notes the decision taken by the SPFL to commence disciplinary proceedings against three clubs following the semi-finals, and we will present Celtic’s position at the relevant hearing.
“The Club has been very clear in our opposition to the unauthorised use of fireworks and pyrotechnics at matches, with their use representing a risk to supporter safety and enjoyment, and, now, to the match and match preparations.
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"The Club will continue its efforts to seek to manage this concerning issue."
The SPFL have previously warned supporters against the use of unauthorised pyrotechnics devices at matches.
An SPFL statement read: "Sunday’s Premier Sports Cup Final was an enthralling match, filled with twists and turns. Both teams deserve huge credit for the part they played in one of the most exciting cup finals in recent memory. Celtic and Rangers put on a display of passionate, dramatic and end-to-end football, which showcased all that is best about our game.
"Everyone at the SPFL would like to pass on our congratulations to the players, management and directors of Celtic on their trophy win, and we also send our commiserations to everyone connected with Rangers, who helped make it such a thrilling showpiece event.
"However, the SPFL, Police Scotland and the Scottish FA have been clear that the unauthorised use of pyrotechnics is illegal and unsafe. Therefore, the disruptive displays which took place before and during Sunday’s match were completely unacceptable and again led to a delay to the start of the match.
"The SPFL will liaise with Police Scotland regarding their investigations into this illegal behaviour and these events will also be considered as part of the SPFL’s ongoing disciplinary investigations into both clubs regarding the use of pyrotechnics.
"The SPFL is awaiting the match delegate’s report following the game, which will also consider other matters, including the unacceptable encroachment of supporters onto the Hampden Park trackside area during and after the match."
Speaking at Celtic's recent AGM, current chairman and former chief executive Peter Lawwell addressed the club's enduring issues with pyrotechnics and fan behaviour.
He said: "Celtic were €90,000 in fines from UEFA. This year we've paid €47,000 in fines so far. It's unacceptable and it is very, very unfortunate.
"We have during my time tried various routes to engage, convince, and look at the ticket allocation but unfortunately to no avail."
