Richard Bowers fired an extra-time winner as Third Division Queen's Park grabbed a shock win over Hamilton.
Richard Bowers was the Spiders' super-sub
The Spiders' David Crawford saved an early Derek Fleming penalty before Frankie Carroll set up Steve Canning for the home side's CIS Cup opener.
Crawford saved a second penalty, this time from Richard Offiong, but the striker eventually lobbed an equaliser.
Offiong was sent off for lashing out at Steve Reilly before the First Division side lost to a cool, lofted finish.
And the Glasgow side deservedly held out to record the biggest surprise of Tuesday's first round ties.
Queen's Park: Crawford, Quinn (Keane 118), Reilly, Sinclair, Dunlop, Kettlewell, Agostini (Ronald 105), Paton, Canning, Carroll (Bowers 71), Weatherston.
Subs Not Used: Molloy, Cairns.
Goals: Canning 6, Bowers 107.
Hamilton: McEwan, Stevenson (Parratt 69), Thomson, Easton, Fleming, Elebert, McArthur, Wilson (Agnew 33), Payo (McLeod 64), Offiong, Gilhaney.
Subs Not Used: McCarthy, Jellema.
Sent Off: Offiong (98). Booked: Wilson, Parratt, Thomson.
Goal: Offiong 72.
Ref: E Smith