Peter MacDonald bagged a brace as Morton tightened their grip at the top of the table with a win against Cowdenbeath.
Craig Moore put the visitors ahead in the 13th minute after some good work by Scott Linton.
With half-time approaching, Scott Taggart fouled Cowdenbeath striker Greg Stewart in the penalty area. James Stevenson saw his spot-kick well saved by Derek Gaston but he was quickest to the rebound, tapping into an empty net.
The hosts pulled a goal back from the spot themselves six minutes after the restart when MacDonald converted following Dean Brett's challenge on Martin Hardie.
And the comeback was complete three minutes later when MacDonald headed in his second to level things up.
Taggart fired them ahead for the first time after 63 minutes with a fine strike from distance before Hardie nodded in a fourth eight minutes later.
Morton: Gaston, Taggart, Rutkiewicz, Reid, O'Ware, Bachirou, Hardie (Halsman 88), Tidser, Wilkie (Wallace 90), MacDonald, Campbell (McMenamin 46). Subs Not Used: Hutton, Weatherson.
Goals: MacDonald 51 pen, 54, Taggart 63, Hardie 71.
Cowdenbeath: Wilson, Brett, Armstrong, Naismith, Adamson, McKenzie, Linton (O'Brien 66), McAllister (Ramsay 87), Stevenson, Greg Stewart, Moore (Coult 74). Subs Not Used: Wight, Milne.
Booked: Brett, McAllister.
Goals: Moore 13, Stevenson 40.
Ref: Iain Brines