The 20-year-old Australian midfielder, who joined St Mirren in October, scored the Buddies' second goal on 31 minutes converting from close-range after good work by Paul McGowan.

Mooy, who was making his first start since late November, played the full 90 minutes.

St Mirren will next face third tier Ayr United in the fifth round.

In Scotland's Premier League, 21-year-old Aussie Ryan McGowan was an unused substitute as Hearts came from behind to win 2-1 at Kilmarnock.

In Scotland's Division Two, Young Socceroos defender Dylan McGowan put in a full shift as East Fife lost 4-2 at home to Livingston.

In England's League Two, Shane Cansdell-Sherriff played a full game at the back as Shrewsbury won 3-1 at Accrington, while goalkeeper Jamie Young put in a full shift as Aldershot beat Bradford 1-0.

In India's I-League, Tolgay Ozbey's 41st-minute header proved the winner as East Bengal defeated Viva Kerala 1-0.