UPDATE 1-Golf-Mickelson holds off Els to win HSBC Champions

* Mickelson wins title for second time

* Els shoots course record but comes up short

* Calamitous front nine ends Woods challenge (adds quotes)

By Nick Mulvenney

SHANGHAI, Nov 8 (Reuters) - World number two Phil Mickelson held off a charging Ernie Els to win the WGC-HSBC Champions by a shot on Sunday for his second success in three years at the $7 million tournament.

The American shot a three-under-par 69 in a dramatic fourth round to finish 17-under for the tournament and pick up his second World Golf Championship (WGC) title and a cheque for $1.2 million.

"To finish the year with this win feels wonderful," said Mickelson, who won his first WGC event at the CA-Championship earlier this year.

"Ernie hit one of the great rounds today ... it feels terrific because I had to fight all of the way, none of it was easy."

The final day had been billed as a shootout between the top two in the world but after number one Woods faltered early on, it was Els who threatened to stop Mickelson reclaiming the title he won in 2007.

Els was one of three players to beat the old course record with a round of 63 on Sunday but the South African found the water at the 18th and had to settle for second place on 16-under.

"Today was a wonderful day," said the 40-year-old. "I really had a good time. I knew the pressure was on. I knew the situation.

"I'm disappointed about (the shot at the 18th), but I'm going to really think about the 63 I shot."

American Ryan Moore carded a 68 for third a further shot back, while Northern Ireland's Rory McIlroy was another who shot a 63 to take fourth on 14-under, one better than American Nick Watney (71) in fifth. TAME TIGER

Woods, who finished with a par 72 for a share of sixth, had a front nine to forget, finding a canal for a double bogey at the third then falling apart after he drove into a bunker off the seventh tee and took four shots to get onto the green.

The 14-times major champion did well to make bogey but Mickelson grabbed a second birdie of the day and moved into a six-shot lead over the world number one.

"Today was anything that could go wrong went wrong for me today," said Woods. "Just one of those days where I just didn't put it together at the right time."

Els, who started the day seven off the pace, had quietly moved up the leaderboard with four birdies in his first six holes before making a 20-foot eagle putt from the fringe of the green at the par-5 seventh to move within a shot of Mickelson.

After he drew level at the 11th, the pair traded birdies through the back nine with Els getting his nose ahead at 16-under courtesy of a superb drive at the 17th.

Mickelson, playing with Woods and Watney in the final group, looked in trouble when his ball went into deep rough at the 16th and his first attempt to get onto the green failed to shift it.

But he sent a 15-foot par putt rattling into the hole and, as he was punching the air in delight at the save, Els's approach shot at the 18th plunged into the middle of the lake.

"That putt was the critical moment," said Mickelson. "It was the best putt I made all week. I knew when I got that putt that I had a chance." Mickelson birdied the 17th to take the lead but flirted with danger by twice landing in deep rough at the 18th before his final approach left him with a simple par putt of less than two feet for the championship.

(Editing by Alastair Himmer. To query or comment on this story email sportsfeedback@thomsonreuters.com)