By Mark Lamport-Stokes
KOHLER, Wisconsin, Aug 17 (Reuters) - Jason Day's breakthrough victory at the PGA Championship served notice that a changing of the guard is now complete with an exciting posse of young guns set to dominate the majors for the next decade.
Newly crowned world number one Jordan Spieth and Rory McIlroy are already established as the game's leading duo but Australian Day, 27, American Rickie Fowler, 26, and rising Japanese talent Hideki Matsuyama, 23, are in hot pursuit.
Six of the last seven major championships have been won by twenty-somethings, proof positive that the 'Big Five' era of Tiger Woods, Phil Mickelson, Ernie Els, Vijay Singh and Retief Goosen is over.