Spieth aiming to be top gun with victory in Ohio

Bridgestone triumph would vault Texan into the No 1 spot

Masters and US Open champion Jordan Spieth will be seeking to unseat Rory McIlroy as world No 1 on Thursday when he tees off in the WGC-Bridgestone Invitational.

Spieth, still smarting from his agonizing failure to win the British Open at St. Andrews last month, headlines the no-cut tournament which includes 48 of the top 50 players in the world.