SHANGHAI — Thousands of fans caused a bottleneck at the entrance to the HSBC Champions, all of them eager to see the Sunday showdown at Sheshan International between Phil Mickelson and Tiger Woods.

The Shanghai surprise? Woods turned out to be merely a spectator, too.

Mickelson built a six-shot lead over the world’s No. 1 player on the front nine, then rallied to beat another familiar foe, Ernie Els, with two clutch putts for a one-shot victory in the final World Golf Championship of the year.

Mickelson closed with a 3-under 69 and won for the first time playing with Woods in the final group.

Even with Woods out of the picture — he shot 72 and wound up five shots behind — Mickelson provided his usual dose of entertainment.

Trailing by one shot, Mickelson whiffed on a risky flop shot below the 16th green, only to save par with perhaps his best putt of the year, an 18-foot slider that dropped on its final turn. He followed that with a 10-foot birdie on the 17th, which turned out to be the difference when Els hit into the water on the par-5 18th and made bogey.

“We all expected that Tiger and myself would be shooting in the mid-60s and pull away a little bit,” Mickelson said. “And yet, our group was not making any birdies. It was the groups in front of us. And I was very fortunate to come out on top by a shot. But this feels terrific, because I had to fight very hard throughout the day. Nothing came easy.”

That was particularly true for Woods.

He looked out of sorts from the start, missing birdie putts of 4 feet and 10 feet, then taking double bogey on the par-3 fourth when he hit into a canal left of the green where residents on the other side routinely dump their garbage.

Hearing a series of camera shutters in the middle of his swing on No. 7 caused him to hit his tee shot into a plugged lie in the bunker, and it took Woods three shots to cover the final 75 yards and reach the green for another bogey.

“Anything that could go wrong went wrong for me today,” Woods said. “Just one of those days.”

It ended with a wedge too strong that went down the bank and into the water on the 18th, then having to wait for Mickelson to tap in for par and walk off the green to affectionate applause.

In the last four times Woods has played in the final group dating to the PGA Championship in August, he has won only once. And the last three times he and Mickelson have played together in the final round, Lefty has come out on top every time.

“I didn’t really envision shooting even par today,” Woods said. “The guys took it deep, and I didn’t.”

Mickelson finished at 17-under 271 and earned $1.2 million for his fourth victory of the year, matching his career-best. And while the PGA Tour does not count this World Golf Championship as official, it sure felt that way.

“It would be great if it would count, but it doesn’t take away from the fact that I beat 15 of the 20 best players in the world, and the gratifying feeling of having this trophy,” he said.

Mickelson became the fourth player to win multiple WGC events, and he joined Woods as the only players to win two in one year. Mickelson also won the CA Championship at Doral by one shot over Nick Watney, the other player in the final threesome Sunday. Watney, calm in the face of so many cameras and so much movement, birdied the last two holes for a 71 and finished fifth.

Els put together a stunning charge on a steamy afternoon, going out in 30 to pull within one shot and taking the outright lead with a birdie on the par-5 14th. He was on the verge of a course record and his first victory in nearly 20 months, leading by one with his tee shot smashed down the middle of the 18th fairway.

His was 218 yards away, his ball on a downslope. Els didn’t think 4-iron was enough, and 3-iron might take him over the green and down the bank into the water. The South African opted to hit a high cut with his 5-wood and “basically duffed it.”

It landed in the middle of the pond.

“But I can’t think about that,” said Els, who started the round seven shots behind. “For me to come back all the way, to actually share the lead at that point, was quite nice. I’m disappointed about that, but I’m going to really think about the 63 I shot.”

He had to settle for a share of the course record, matched earlier by Rory McIlroy, who finished fourth, and Daisuke Maruyama. It was far more meaningful to McIlroy, the 20-year-old from Northern Ireland who has finished among the top five in six of his last seven tournaments to move to No. 2 in the Race to Dubai on the European Tour.

Ryan Moore, who only qualified for the HSBC Champions by winning his first PGA Tour event in August, closed with a 68 to finish third, two shots behind Mickelson. It should be enough to move him into the top 50 in the world.

“That’s my goal every tournament, even just going into the weekend, to just have a chance to be in the mix of things,” Moore said. “And I did that this week.”

Mickelson has won the HSBC Champions twice in three years, while Woods has yet to win. Even sweeter is playing with Woods, although Lefty didn’t realize it was the first time he had won while playing with Woods in the last group.

“It always feels good to win any tournament, but certainly when you have a chance to go head-to-head,” he said. “Although, I know he didn’t play his best today.”