American Jason Dufner is the last name to be added to the PGA Grand Slam of Golf which will be held at Port Royal Golf Club in October, following his win at the PGA Championship.He joins Australia’s Adam Scott who claimed the Masters, Britain’s Justin Rose who won the US Open and last month’s Open winner Phil Mickelson.Dufner, 36, clinched his first major title by two shots at Oak Hill Country Club to erase the memories of his stunning collapse two years ago.He said: “It’s a tough golf course and it probably hasn’t hit me yet. To come back from a couple of years ago in this championship when I lost to Keegan (Bradley) in the playoff, to win feels really, really good.”The Slam in Port Royal invites the year’s four major winners.The Bermuda tournament offers a purse of $1.35 million with the winner receiving $600,000. Second place is worth $300,00, third place $250,000 and fourth place $200,000.Aired on the TNT network, the tournament has, in the past, reached a worldwide audience of 88.9 million.Established in 1979, the Grand Slam has grown from an 18-hole, single-day charity event to a 36-hole annual showdown that matches professional golf’s best against each other.