SHANGHAI — Justin Rose posed with the trophy from the balcony high above the 18th green at Sheshan International, a moment that didn’t seem possible.

He started the final round eight shots behind Dustin Johnson, the No. 1 player in the world.

“The beginning of the day, I was playing for second,” Rose said.

The HSBC Champions turned into a shocker in Shanghai when Johnson went into the PGA Tour record books for all the wrong reasons.

Instead of becoming the first player to win three World Golf Championships in one year, he tied a record for losing the largest lead in the final round. Six shots clear of the field, Johnson didn’t make a single birdie on a wild, wind-blown Sunday for a collapse that even Rose didn’t see coming.

Only when he saw a leaderboard behind the 14th green and realized he was three shots behind did Rose think he might have a chance. He got up-and-down with a tough bunker shot for birdie, then made a 10-foot par save at the 15th to stay in the game. He birdied the next two holes.

As Rose was signing for a 5-under 67, he looked up and saw Johnson’s last hope for eagle on the 18th hole tumble off the side of the green and into the water.

“It’s the kind of day you certainly don’t expect,” Rose said after his two-shot victory. “It’s the kind of a day you hope for – dream for – but a lot of things need to go your way in order for a day like today to happen, coming from eight shots behind, especially going against a player like DJ.”

Johnson certainly did his part. He shot 77, his highest final round with the lead since an 82 at Pebble Beach in the 2010 U.S. Open.

PGA TOUR: Ryan Armour shot a 4-under 68 to earn an impressive first career win at the Sanderson Farms Championship in Jackson, Mississippi.

Armour started the final round with a five-shot lead and was never seriously challenged. The 41-year-old won for the first time in 105 career starts, finishing at 19-under for a five-shot victory over Chesson Hadley.

CHAMPIONS TOUR: Bernhard Langer beat Miguel Angel Jimenez on the second playoff hole to win the PowerShares QQQ Championship in Thousand Oaks, California.

LPGA: Cristie Kerr holed a 35-foot birdie putt on the final hole for an even-par 71 and a one-shot victory in the Sime Darby LPGA Malaysia in Kuala Lumpur, Malaysia.