NOBM coach Craig Gowler said Donaldson was outstanding throughout the tournament, particularly in the semifinal when they beat Rowzy Pegasi 17-0.
"We were struggling and then three moments of brilliance from Zac led to three tries."
Captain Sean Skeet was impressive with his aerial play. Jack Nelson-Murray and Ricky Hayes were other forwards to impress.
"I was rapt we didn't concede any points for the second consecutive year here," Gowler added.
Saturday's games were played in temperatures around the 32 degrees and 90 per cent humidity. NOBM beat Indonesian side Hanoman 57-0, Papau of Papua New Guinea 40-0 and a Japanese Selection 48-0.
Yesterday Sydney team Waverley defaulted to NOBM because of a high injury tally which gave the defending champs a breather before their semifinal.
In their final NOBM beat Chillies, a selection of Kiwi and Aussie players, 47-0.