The Inverness manager’s team talk drew on the embarrassment but, as a one-sided contest unfolded, there was never any serious risk of a shock for the May 2015 winners.
While Caley Thistle’s financiers will yearn for an Old Firm money-spinner in the last 16, Robertson would prefer a winnable home tie from today’s fifth-round draw.
“Our start made it a comfortable afternoon,” the former Hearts striker said. “The early goal settled us. It was professional. People go on about landing a big tie and making some money. I just want to progress as far as we can. We want to win it.”
East Kilbride came into the match on a run of 11 straight wins, and with no goals conceded in their last four matches. They must have held genuine hope of creating an upset.
There was a calm authority in the hosts’ play from the off – and they grasped a sixth-minute lead.
Stuart Malcolm’s men had no time to settle before Aaron Doran’s dangerous cross broke to Jordan White to control and slam in a low, angled finish from seven yards.
After 21 minutes, Doran curled in a low finish from the edge of the box for the second and a Liam Polworth rocket bulged the net from 16 yards for the third.
It proved a more subdued second period, but the fourth, a powerful Doran cross, killed any hopes of a Kilby comeback.