Mayo survived a Connacht Championship scare against London after being taken to extra-time by the Exiles in Ruislip.
Sunday's game went to extra-time after London, aided by a Paul Geraghty goal, led at half-time before a 70-minute score of 1-9 to 0-12 meant the need for extras.
Mayo's bacon was saved by late scores from Trevor Mortimer and Kevin McLoughlin.
Mayo finally found their form in extra-time and led by four, only for Sean Kelly's goal to have them on edge again.
However, they held on as Andy Moran's sixth point of the day saw them emerge as 0-19 to 2-10 victor, setting up a provincial semi-final with old rivals Galway.