Ujdur opened the scoring in the 15th minute for Olympic shortly before Lachlan Rose answered back for the hosts minutes later.
Darcy Burgess ensured Olympic would go into the break on a high after his goal in the 33rd minute gave the visitors the lead for the second time in the game.
Rose capped off a successful opening to the second half for the Bulls with a goal in the 55th minute but Roy O’Donovan put Olympic back in the lead from the penalty spot in the 67th minute, shortly before Ujdur bagged his second in the 71st minute to seal the result.
Ex Bull charges in for Blues win
FORMER Bulls star Nikola Ujdur has become the unlikely hero for Sydney Olympic, with his second goal securing three crucial points for the Blues as they defeated Northbridge Bulls 4-2 at Sydney United Sports Centre on Saturday afternoon.