The backpost header to Leon Balogun's knock-on avoided the offside flag to cancel out Moi Elyounoussi’s diving header opener for Celtic after 23 minutes.
After a slow start the opener lifted the game to life and after the Colombian’s equaliser – his 55th league goal for Rangers in the season of their 55th league title – Ryan Kent also stung the palms of Scott Bain before Elyounoussi had another header scooped off the line by Allan McGregor.
BBC pundit Pat Nevin hailed Morelos’ eventual equaliser – his first ever against Celtic – and his celebration: “Morelos finally, finally has scored against Celtic in his 13th Scottish Premiership appearance against them. There was a suspicion of offside there but there was no offside - he timed his run perfectly.
"He's turned around and said something to the crowd... but there's no crowd there."