Eventually, the Kiwis were able to hold on for a 21-19 win and square the match at one set each.
The deciding third set was even at the start with New Zealand ahead 9-7 but Cyprus came back to 10-all and with an upset on the cards the mainly Australian crowd got behind the underdogs.
But that was all the incentive the O'Dea brothers needed to show their class as they scored four excellent points to surge ahead 14-10. A point each to serve was good enough for them to win the third set 15-11 and take the match 2-1.
It was far from a complete performance by the Kiwi siblings but they will be pleased to have got the win as they prepare for harder challenges to come in pool play. They play Mozambique tomorrow and England on Sunday with quarter-finals to start on Tuesday.
Western Bay athletes in action on Saturday
Swimming
Tem Strickland (Cook Islands) 100m freestyle heats 1.48pm
Beach volleyball
2.30pm NZ women (Kelsie Wills, Shaunna Polley) v Rwanda
Sunday
Hockey
1.30pm NZ women (Sam Charlton, Rose Keddell, Frances Davies, Amy Robinson) v Canada
Beach volleyball
8pm NZ women v Singapore
10.30pm NZ men v England
Live coverage: TVNZ free-to-air