Braithwaite blasted 11 boundaries and eight sixes in his whirlwind innings.
Collegiate tried six bowlers with Joel Clark getting some stick with 52 taken from his five overs, while Ben Kelt was taken off after an over which cost 26.
Clark and O'Leary got the wickets.
Collegiate's next game is against Stephenson Academy at the Franklyn Stevenson Academy, overnight NZ time.
Meanwhile, Wanganui Collegiate 1st XI player and temporary member of Marton Saracens, Sam Sherriff, has been named in the Central Districts Under 17 team to contest the national tournament in Auckland, starting on Saturday.
The batsman Sherriff is the sole Whanganui player in the squad, alongside four from Taranaki, four from Nelson, two Hawke's Bay and one each from Manawatu and Horowhenua Kapiti.
The tournament runs to January 20.