Gers players took issue with Scott Brown after his celebration at Parkhead this afternoon.
It led to shirts torn and players hitting the ground.
Celtic held on to win 2-1 and go 13 points clear at the top of the Ladbrokes Premiership but the action continued after the final whistle.
A number of players and other members of each bench were involved in a melee.
Andy Halliday and Brown initially involved and Rangers substitute Wes Foderingham being dragged away from the flashpoint.
French striker Odsonne Edouard opened the scoring in the 27th minute before Morelos was shown a straight red card by Bobby Madden for throwing an elbow at Hoops skipper Scott Brown.
Steven Gerrard’s 10-men sensationally levelled through Ryan Kent in the 63rd minute and when Celtic defender Dedryck Boyata went off injured, after interim manager Neil Lennon had used all three substitutions, the numbers were levelled.
But in the 85th minute James Forrest’s finish from 12 yards took the hosts a step closer to their eighth successive title.