St Johnstone scored four goals in extra-time to end a brave CIS Cup fight by Third Division Elgin City.
Elgin's Chris Gardiner had an effort blocked on the line, while Saints' Peter McDonald and Paul Sheerin went close as the home side dominated.
Sheerin scored from the spot after goalkeeper Kieran Renton brought down Martin Hardie in the box.
Ryan Stevenson fired home and Steven Milne headed in before Steven MacKay turned the ball into his own net.
St Johnstone: Halliwell, Lawrie, Stanic, Mensing, Anderson, James, Young (Jackson 65), Hardie (Stevenson 100), Milne, Coyle (MacDonald 67), Sheerin.
Subs Not Used: Dyer, Cuthbert.
Goals: Sheerin 98 pen, Stevenson 105, Milne 108, Mackay 114 og.
Elgin: Renton, Kaczan, Dempsie, Easton, Dickson, Hind (Low 111), Gardiner (Campbell 61), Booth (Cooke 91), Johnston, Charlesworth, Mackay.
Subs Not Used: Finnigan, Knight.
Booked: Charlesworth, Renton, Campbell.
Ref: M Tumilty