Melbourne Airport was thrown into chaos as a power fault brought check-in and baggage services to a standstill.
Energy company Jemena reported on its website that more than 34,000 customers in Melbourne's north-west were being affected by the power outage.
A Jemena spokesperson told the ABC a fault during installation and testing at a Keilor terminal resulted in the widespread blackout.
Aberfeldie, Airport West, Ascot Vale, Essendon, Flemington, Moonee Ponds, Niddrie and Strathmore were among the suburbs affected.
Power has since been restored.
Melbourne Airport said in a tweet it was investigating the cause of the power disruption at its terminals and apologised for the disruption.
Check-in and baggage services have since resumed.
Affected residents are encouraged to report any electrical outages on 131 626.