ARDMORE, Pa. —

As rain lashed Merion Golf Club last Monday, alarm rose with the water.

Whitecaps lapped in the creek at the 11th hole! Trout swam in the flooded bunker! The course was softer and pudgier than Phil Mickelson! Time to bring out the octopus pants!

Stay calm, said Jarrett Kling, a longtime member at Merion. He spoke confidently of subterranean drainage systems and speedy, undulating greens. He scoffed at predictions of anyone shooting 20 under par at the U.S. Open. He promised the tournament would be worthy of the Golf Channel, not the Weather Channel.

“Merion will be what it wants to be,” Kling assured.

And he was right. Merion menaced with its narrow fairways and sloping greens and thick rough that required a pith helmet and a safari guide. Yet while the course was mostly forbidding, it was also grudgingly forgiving at times, autocratic but occasionally democratizing.

Late Saturday, after Rory McIlroy shot a numbing 75, an acquaintance ran into McIlroy’s father, Gerry, on the course.

“Merion won,” the acquaintance said in consolation.

McIlroy smiled and shrugged.

Merion also humbled Tiger Woods and spawned the Twitter message of the week from novelist and golf writer Dan Jenkins. After Woods shot a 76 on Saturday, Jenkins wondered whether Woods’ girlfriend, champion skier Lindsey Vonn, had asked, “Did you, like, miss a gate on the course or something?”

Woods was the subject of countless rumors about his living arrangements during the Open, all entertaining, none necessarily reliant on the truth.

One rumor, debunked by a police officer assigned to Woods, had him installing a pool at his rental house. On Sunday, Joe DiTomo, a volunteer driver for the players, said that Woods reportedly grew upset with the house and moved into a hotel.

“I wouldn’t repeat it,” DiTomo said, “but I heard it from a nun on the way to church. I didn’t realize nuns followed golf.”

If Merion proved heartless to the favorites, it also showed reluctant compassion for others. After posting an 85 on Saturday, a score higher than the temperature, Shawn Stefani shot a hole-in-one Sunday on the 229-yard, par-3 17th. Until that moment, Stefani was best known for shooting deer.

His 4-iron missed the green entirely, landing in the rough to the left. At that point, Stefani was 20-over par, apparently wearing out the 1962 quarter, a gift from his girlfriend, that he used to mark his ball. But this time the ball trampolined onto the green and did an arcing, smiley-face roll about 50 feet into the cup.

It was the 43rd ace at a U.S. Open and the first at an Open played at Merion. A PGA Tour rookie, Stefani high-fived his caddie and did a few muscleman flexes. Then he ran and kissed the rough where his shot had bounced. The crowd erupted.

“We’re in Philly,” Stefani said. “I know they can be tough on you and they can love you forever.”

This weekend, much love was showered on LaRue Temple of north Philadelphia, a frayed neighborhood that could hardly be more strikingly different from the moneyed, Main Line environs of Merion.

Most pro golfers travel with their own caddies. But Michael Kim, a 19-year-old amateur from Cal-Berkeley, arrived without anyone to work his bag. Temple, who has caddied at Merion since 1997, happened to be in the parking lot Monday, taking his mother to the course for the first time.

“She wanted to see Tiger Woods,” Temple said.

The caddie master approached him. Suddenly, Temple no longer needed his tickets to get into the Open. His buddies in the crowd serenaded him with calls of “LaRue, LaRue.” For 12 holes Saturday, Kim said with a laugh, Temple “was getting more cheers than I was.”

On the 15th hole on Saturday, two strokes off the lead, Kim allowed himself a brief but naïve moment to ask, “What if I won?”

Then he bogeyed 16 and 18 and double-bogeyed 17.

“This is Merion,” Temple said knowingly. “Merion stands up.”

Kim should not have felt too bad. On Friday, a frustrated Jason Dufner tossed his wedge into a creek. On Sunday, Dufner shot an impressive 67, tied for the best round of the day despite triple-bogeying No. 15 after his tee shot landed in somebody’s backyard.

Luke Donald entered the final round two shots off the lead, only to plunk a volunteer, apparently in the head. Then, with his bare right foot planted in a creek, Donald chipped into a bunker. Steve Stricker, one shot behind after three rounds, took an 8 count on No. 2 on Sunday, a triple bogey and a career high for a hole.

Mickelson, the third-round leader, wore gunslinger black on Sunday but misfired with three bogeys and two double bogeys.

“Man,” he muttered to himself.

In the end, no one was under par. Justin Rose won, but the real victor was Merion.