Rousing Kilmarnock delivered again to sink Treble winners Celtic 1-0 thanks to Marley Watkins' sliding strike to leave the Treble winners suffering Viaplay Cup woe.
Derek McInnes' side wouldn't be denied and enter the hat for the last eight after the Wales international's perfect run to turn home Danny Armstrong's teasing cross as Brendan Rodgers looked away.
The win marks the end of the Irishman's perfect Cup record and likely offers up a dose of reality of what he must improve on before the window shuts.
Celtic huffed and puffed but were reduced mostly to half chances and potshots in the frantic final exchanges. The much-maligned surface looked extra dry upon kick off and, perhaps, it played a part in Celtic star pair Kyogo and Maeda hitting the deck with Swan Lake-like synchronicity.