Ayr United extended their lead in the Championship to five points but were left to rue a second home draw in a week.
Ian McCall’s men had to play the last half hour with only ten men after Craig Moore was shown a straight red card for a retaliatory back-heel kick on Gregor Buchanan who was booked for the original foul.
But they dug deep to win a valuable point and preserve their unbeaten record at Somerset Park this season.
A goalless first-half only came to life late on when Morton spurned two great opportunities to halt Ayr in their tracks.
In 36 minutes Liam Smith was short with a pass back and Gary Oliver galloped clear only for his shot to be blocked by Ross Doohan who advanced off his line.
Two minutes later, Ayr were found wanting at the back again when Bob McHugh was able to race clear but he slid his shot wide of Doohan’s right hand post.
As always, Ayr looked to their free-scoring striker Lawrence Shankland to break the deadlock and he almost obliged four minutes before the interval. The 23-year-old tried to beat Derek Gaston with a curling shot after finding himself in space but the keeper pushed his effort wide for a corner.
Ayr began the second period well with Moore heading wide and Robbie Crawford and Mark Kerr having shots saved.
But they shot themselves in the foot on the hour when Moore was dismissed.
Morton almost immediately made their numerical advantage pay when Oliver hit the foot of the post with an angled shot.
And in the final minute it took a goal-line clearance by substitute Michael Moffat to keep out a net-bound header from Buchanan.