UNIVERSITY PLACE (Washington) - Two down and two to go - and Jordan Spieth believes that an unprecedented clean sweep of golf's four Majors in the same year is possible.

The greats of the game - Ben Hogan, Arnold Palmer, Jack Nicklaus, Gary Player and Tiger Woods - have all tried and failed to achieve that feat.

Spieth, though, has now put himself in that Grand Slam position by winning the US Open in thrilling style at Chambers Bay on Sunday, two months after lifting his first Major at the Masters.

It is a mouth-watering prospect which will take him to St Andrews for the British Open next month and to Whistling Straits in Wisconsin for the PGA Championship in August.

It is a prospect that the 21-year-old has clearly considered, but he does not want to get too far ahead of himself.

"I think it's in the realm of possibility," he said shortly after his US Open win by a nerve-jangling one shot after Dustin Johnson blew his chance to force a play-off by three-putting the last hole. "I'm just focused on the Claret Jug (British Open) now."

Spieth's two wins mean that the four golfing Majors are now held by just two men - himself and 26-year-old Rory McIlroy, who won the British Open and PGA Championship last year. The Northern Irishman tied for ninth at level par on Sunday, five strokes behind the American.

Although the talk is of a rivalry between the two young guns that will light up golf for the forseeable future, Spieth said he does not yet consider himself to be in the same elevated bracket as McIlroy.

"It's kind of cool. I think to have two players holding the four Majors and Rickie (Fowler) having the fifth (Players Championship)," said the American. "It's awesome that the game is in young hands.

"I don't think there is much of a rivalry. Rory has four Majors and dozens of wins and I'm just starting out.

"Again, I'm certainly quite a bit younger than he is. I'm just happy to have this and to be chasing that No. 1 spot that he holds. So I'm certainly focused on that."

On Sunday, Spieth sank a curling 28-footer to birdie the 16th hole and forge three ahead, then shrugged off a double-bogey at the 17th before becoming just the sixth player to slip into a green jacket and hoist the US Open trophy in the same year.

Though he birdied the par-five 18th to end a wildly fluctuating final round of high drama with a one-under 69, he then had to watch as fellow American Johnson, in the last pairing, had a 12-foot putt to win it at the 18th.

Johnson's eagle attempt slid past the cup and he then missed a four-foot birdie putt coming back to squander the chance of forcing an 18-hole play-off at Chambers Bay.

Spieth posted a 275 total on a challenging links-style layout that firmed up under a baking sun as he became the youngest winner since Bobby Jones in 1923.

"I'm still amazed that I won, let alone that we weren't playing tomorrow," Spieth said. "So for that turnaround right there, to watch that happen, I feel for Dustin. But I haven't been able to put anything in perspective yet."

Johnson, seeking his first major crown, had to settle for a share of second place with South African Louis Oosthuizen, who sensationally birdied six of the last seven holes, including five in a row from the 12th, for a 67.

South African Branden Grace, whose hopes evaporated with a double-bogey at the 16th where his tee shot ended up on railroad tracks out-of-bounds, carded a 71 to share fourth place on 277 with Australians Adam Scott (64) and Cameron Smith (68).

AGENCE FRANCE-PRESSE, REUTERS