BLOOMFIELD TOWNSHIP, Mich. - All it took was one record-tying round and several claps of thunder for Oakland Hills to finally look vulnerable Saturday in the PGA Championship.

Andres Romero kept his calm and played a third round he described as “almost perfect” in making seven birdies to become only the seventh player to shoot 5-under 65 in a major at Oakland Hills.

Then came Mother Nature, who really brought “The Monster” to its knees.

Thunderstorms swamped the golf course before 36-hole leader J.B. Holmes and five guys chasing him could even tee off. More than four hours later, the PGA of America told everyone to return Sunday for what could be the first 36-hole final at a major in more than 40 years.

“It will be like college again — playing 36 in one day,” Holmes said. “It happens, and everyone else has to do it, too. So we just have to go out there and deal with it. They’ve got 12 hours to work on the golf course, and it needed the rain.

“We’ll see what it looks like tomorrow.”

The rain could reshape the character of the final major. Holmes was at 1-under 139, the only player to beat par over two days, but so much rain was sure to take the fire out of the Donald Ross greens that had made players be on the defensive.

“I think it is fair to say they will be significantly more receptive,” said Kerry Haigh, the PGA official in charge of setting up the course.

Former U.S. Open champion Angel Cabrera ripped a 3-wood down the first fairway when the round was suspended at 2:16 p.m. Hours later, as he looked toward more dark clouds to the north, he contemplated a marathon Sunday.

“It will be easier,” Cabrera said. “There is justice.”

Romero made it look easier even before the storm clouds gathered. The PGA helped slightly by pouring extra water on the greens overnight and trimming some of the rough in the landing areas.

But the 27-year-old Argentine did his part.

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Romero first showed his explosive style last year at Carnoustie, where he made 10 birdies in 16 holes during the final round of the British Open and finished one shot out of a playoff. He was firing away at Oakland Hills, hitting a 3-iron to 6 feet on the par-3 ninth and making his final birdie with an 8-iron to 6 feet from a scary pin on the 16th.

“I played an excellent round,” Romero said through his interpreter, Marcos Virasoro. “Almost perfect. Yesterday, I finished very mad with my round and now after this 18 holes, I can’t believe it. I will have a chance for tomorrow. I have to wait, but it’s great to be here.”

He was at 2-over 212, and had no idea just how long he would have to wait to see where it stacked up.

The good news? He can get some rest. The third round was to resume at 7:15 a.m. Sunday with six players facing 36 holes, while Romero won’t have to show up until noon and play only 18.

The last major champion to play 36 holes on the final day was Peter Thomson in the 1965 British Open. Tiger Woods played 27 holes on Sunday when he won the rain-delayed Masters in 2005.

Romero was among 25 players from the 73-man field who completed their rounds Saturday.