Bailly, 28, impressed for Erik ten Hag's side and laid on striker Rashford for the Red Devils' third goal of the game.
The Ivory Coast international picked up the ball in the centre circle before going on a darting run past one man.
He then slotted the ball through four defenders, picking out Rashford in the process, who fired under the goalkeeper to score on 78 minutes.
United had earlier found themselves 1-0 down inside five minutes, when Chris Ikonomidis put the hosts ahead.
It delighted the home crowd, as the Aussie's around the stadium sang 'you're getting sacked in the morning', in the direction of Ten Hag.
The Red Devils did level through Scott McTominay two minutes before half-time, though, before Fred put his side ahead deep into added time at the end of the first 45 minutes.
Bailly produced his moment of magic for Rashford to score on 78 minutes making it 3-1, and Edmund Lupancu put through his own net right at the death to complete the scoring.
Bailly had previously earned high praise following his impressive second-half display as United beat Liverpool 4-0 in their first pre-season game in Bangkok, Thailand on Tuesday.
He was involved in his side's fourth goal, storming from his box to the opposition's, before Facundo Pellistri slotted in past Liverpool goalkeeper Adrian.
The defender will be hoping to cement a place in Ten Hag's side ahead of the new season, with United set to sign centre-back Lisandro Martinez from Ajax.
United face Crystal Palace next at the Melbourne Cricket Ground on Tuesday in their third pre-season clash of the summer, with Ten Hag hoping to make it three wins from three.