Alexander King’s early header secured Morton a 1-0 cinch Championship victory over mid-table rivals Raith, who ended the game with nine men.
Midfielder King headed home after just 82 seconds and that was enough for Morton to extend their unbeaten league run to four matches.
Raith went closest to an equaliser when Lewis Vaughan’s superb long-range effort struck the crossbar early in the second half.
The visitors finished the game with nine men after Tom Lang and Vaughan were both dismissed in the closing stages for second bookable offences.
King gave Morton a flying start when he planted a neat header into the bottom corner following Calvin Miller’s fine run and cross.
Morton threatened to increase their early lead through Lewis McGrattan, Calum Waters and George Oakley’s header.
Vaughan headed wide for Raith and Darragh O’Connor’s header was held by Raith goalkeeper Jamie MacDonald before the break.
The away side went close again when Vaughan’s powerful shot hit the crossbar and MacDonald denied Morton a second goal when keeping out Grant Gillespie’s late effort.