Masters champion Jordan Spieth added another chapter to golf's record books with a nerve-jangling, one-shot victory at the US Open after Dustin Johnson blew his chance to force a playoff by three-putting the last.

American young gun Spieth sank a curling 28-footer to birdie the 16th 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.

Spieth's achievements
Spieth joins Woods, Nicklaus, Palmer, Hogan and Wood as the only players to have won the Masters and US Open in the same year.
Spieth became the youngest winner of the US Open since Bobby Jones in 1923.
The American also became the youngest player to win back-to-back majors since Sarazen in 1922.

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

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

The 21-year-old Spieth posted a five-under total of 275 on a challenging links-style layout that firmed up under a baking sun as he became the youngest winner of the US Open since Bobby Jones in 1923.

"I'm still amazed that I won, let alone that we weren't playing tomorrow," Spieth told reporters.

"So for that turnaround right there, to watch that happen, I feel for Dustin."

The victory saw Spieth join Tiger Woods, Jack Nicklaus, Arnold Palmer, Ben Hogan and Craig Wood as the only players to have won the Masters and US Open in the same year.

I feel like it's sort of one that got away. I don't think I've ever hit the ball as well in a major championship

Rory McIlroy, World number one

"It's cool to be able to have two legs of the grand slam now, and to conquer golf's hardest test. The US Open is conquering the hardest layout in all of golf."

Spieth, who stunned the golf world with a wire-to-wire victory by four shots at the Masters in April, became the youngest player to win back-to-back majors since Gene Sarazen in 1922.

Meanwhile, world number one Irishman Rory McIlroy had earlier sent a tremor of excitement across the course as he racked up six birdies in his first 13 holes to reach two under for the tournament, just two off the lead.

The Northern Irishman drained a 70-footer at the par-four 13th to spark thunderous roars from the grandstands but bogeyed the 15th and 17th on the way to 66 and a tie for ninth at level-par.

"I feel like it's sort of one that got away, especially the way I putted this week," he said.

"I don't think I've ever hit the ball as well in a major championship."

World rankings:

1. Rory McIlroy (Britain) 
2. Jordan Spieth (U.S.) 
3. Dustin Johnson (U.S.) 
4. Justin Rose (Britain) 
5. Bubba Watson (U.S.) 
6. Jim Furyk (U.S.) 
7. Henrik Stenson (Sweden) 
8. Jason Day (Australia) 
9. Sergio Garcia (Spain) 
10. Rickie Fowler (U.S.) 

Source: Reuters