OSCA'S founding partner The Chartered Institute of Management Accountants (CIMA), launched CIMA Mayor's Trophy (CMT) as a corporate social responsibility projects in 2005. Over the next 15 years CIMA made tremendous progress in its community outreach efforts through CMT - paving the way to establish OSCA in 2020. CMT still remains CIMA Canada's feature community, corporate and media engagement event held annually in June, while its school cricket programs have been transferred over to OSCA to expand the programs province wide.

In 2005 CIMA formed a  partnership with the City of Toronto Parks, Forestry & Recreation Department the event is attended by the Mayor of Toronto, the Chief of Police, corporate CEOs, media personalities and prominent Torontonians to celebrate Toronto's diversity through the game of cricket. The event has grown in popularity and profile winning several international awards from the International Cricket Council (ICC).

CMT brings together a wide cross section of Toronto Communities through cricket. The event has attracted media, Transit, Finance and the Public Sector organizations to a unique Toronto celebration. CIMA Media Cricket Tournament is a component of the CIMA Mayor’s Trophy and is a major media event in the City. Cricket teams from CBC, Rogers, Globe & Mail, Toronto Star, Toronto Sun, Citytv, OMNI TV and Metro News regularly take part in this annual event. The Public Sector cricket team includes the Mayor, City Councillors and Public Sector executives.