BEIJING • The lane to historical supremacy remains wide open.

Michael Phelps powered to a world-record 4-minute, 3.84-second victory in the 400-meter individual medley Saturday. It was an exclamation-mark start for his plan to swim to a record eight gold medals.

He was propelled to his record by plenty of pomp and ceremony. After Phelps climbed victorious from the pool, he exchanged a wave with George W. Bush, dressed casually in shirt sleeves, and his father, George H.W., who wore a dark suit.

Phelps said he was inspired in the pool by the thought two presidents were cheering for him while they waved the American flag.

“That was a pretty cool feeling,” Phelps said.

The Bushes watched a close, dramatic race. Phelps’ first win did not come easily. He trailed Hungary’s Laszio Cseh, who won the silver, at the first wall and American Ryan Lochte, who finished third. Lochte later briefly pushed to the lead.

“I wasn’t really comfortable with having that close of a race,” Phelps said.

His discomfort proved dangerous. At the 200-meter mark, he powered to the lead, and that was it. No one had a chance.

He emerged from the water with a giant smile. Later, his eyes were watery on the medals stand. He tried to sing along to the national anthem, but his surging emotions wouldn’t let him.

“I don’t know why,” Phelps said. “I wanted to sing … but I couldn’t stop crying.”

Phelps won his medal at the funky, otherworldly Water Cube, a translucent, blue-toned arena that looks as if it’s covered in a gigantic bubble wrap.

He entered the arena to great applause and followed his meticulous prerace routine. He vigorously dried his block and then stretched his right leg, followed by his left.

Two minutes before the starting gun, he finally removed his iPod earphones before vigorously shaking his arms.

He was ready to embark on the road to eight medals. Millions were cheering while watching TV back in the United States. The Bush dynasty was clapping here in Beijing.

But not everyone applauds Phelps’ ambitious plan. Last week, Brazilian swimmer Thiago Pereira said Phelps “is an amazing athlete, but he’s human. … One day someone is going to beat him.”

That someday and that someone didn’t arrive today in Beijing. Pereira finished eighth, or dead last.

In other late finals:

American Katie Hoff won a bronze in the women’s 400 individual medley. Australian Stephanie Rice won the gold while setting a world record.

American Jensen Larsen won bronze in the 400 freestyle.

The U.S. women were second in the 400 freestyle relay with Natalie Coughlin, Dara Torres, Lacey Nymeyer and Kara Lynn Joyce.

Michael Phelps swam the breaststroke leg during his gold medal performance in the 400 meter individual medley early Sunday at the Water Cube in Beijing. Photo by MARK REIS, THE GAZETTE