 Mayoh made his first grade debut for North Sydney in round 1 1979 against Cronulla-Sutherland at North Sydney Oval which ended in a 7-34 loss.Mayoh made a total of 6 appearances for Norths in his debut year as the club finished last on the table and claimed the wooden spoon after winning only 2 games all year.After another two seasons spent near the bottom of the table, Norths fortunes changed in 1982 as the club finished third under the coaching of Ron Willey.