ROME — One after another, the records kept falling.

Two in semifinal heats. Two more in one race. When the night was done, six world records had been broken — and there were only four finals on the program.

“We were talking in the back about how this is just ridiculous,” said 42-year-old Dara Torres, who has pretty much seen it all during her long swimming career. “But this is the last time it’s going to happen. Then we can go back to real racing.”

The swimming part of the world championships began Sunday, and it went pretty much as many had predicted in the last hurrah for high-tech bodysuits. They’ve been banned starting in 2010, but for now, pretty much anything goes one last time.

On a night when Michael Phelps didn’t set a world record, just about everyone else who squeezed into one of those skintight suits did some rewriting of the record book.

Some enjoyed the spectacle. Others found it ludicrous.

“The world championships are a laughingstock to the world of swimming,” said Dawn Fraser, who won Olympic gold medals for Australia at the 1956, ’60 and ’64 Olympics. “Those six world records should be immediately rescinded. The suits and their buoyancy offer an unfair advantage which is plain to see.”

Germany’s Paul Biedermann, wearing a polyurethane suit that soon will be headed for the scrap heap, beat his qualifying time from a month ago by a staggering 61⁄2 seconds and broke an iconic world record, Ian Thorpe’s 7-year-old mark in the 400-meter freestyle.

“I expected someone to break the world record. I didn’t expect it to be me,” said Biedermann, whose time of 3 minutes, 40.07 seconds beat Thorpe by a hundredth of a second. “This suit makes me really fast. Honestly, I think it (cuts off) two seconds in the 400.”

Australia’s Eamon Sullivan, who holds the world record in the 100 free but missed these championships because of an illness, found it amazing that a relatively unknown swimmer snatched away a record held by one of the greatest ever.

“No disrespect to Biedermann, but he’s not in the same class as Ian Thorpe,” Sullivan said. “It’s obvious what the suits are doing.”

The German wasn’t the only one going really, really fast at the Foro Italico.

An even older world record by Inge de Bruijn, which had stood since the 2000 Sydney Olympics, also went down. Sweden’s Sarah Sjostrom got that one in the semifinals of the 100 butterfly, her time of 56.44 erasing the mark of 56.61.

Ariana Kukors, who didn’t even qualify for the 200 individual medley at the U.S. trials but got in when a teammate scratched, now holds the fastest time ever.

“Nobody expected anything from me in this event,” Kukors conceded.

She, too, did it in a semifinal heat, wearing a new-age Jaked suit when she went 2:07.03 to easily beat Stephanie Rice’s 2:08.53 that won gold in Beijing.

“Even if it was me breaking a world record, I wouldn’t be jumping for joy,” Torres said. “Because you know it’s the suit.”

The record book was so worthless that two marks fell in a single race. Germany’s Britta Steffen was credited with a record of 52.22 in the 100 free for her opening leg of the 400 free relay, but the Netherlands came back to win the race — with a record-breaking time, of course: 3:31.72.

In fact, runner-up Germany and third-place Australia also broke the previous mark of 3:33.62.

The Italian fans had plenty to cheer about when Federico Pellegrini became the first woman to break the 4-minute barrier in the 400 free. She patted her heart and waved to the near-sellout crowd as she walked off the deck with a time of 3:59.15, taking down her own month-old record.

“Usually, once swimmers dive in the water you don’t hear the crowd cheering,” Pellegrini said. “But this time it was completely different. I could hear the crowd cheering.”

Phelps had an off night. His new windmill stroke just slowed him down. He left his teammates with some catching-up to do. Heck, he didn’t even get a world record on a night when it seemed everyone did.

Yet, when it was done, Phelps found himself in that same, ol’ place — top of the medal stand.

He was actually the slowest member of the U.S. 400 freestyle relay team, but the guys picked him up and beat the French again, just as they in that memorable race last summer at the Beijing Olympics.

“The best thing about this relay was they carried Michael,” said Bob Bowman, Phelps’ coach and also in charge of the U.S. men’s team. “We need the other people to step up.”

They sure did — especially Nathan Adrian on the anchor leg. His blistering down and back was reminiscent of Jason Lezak’s amazing swim at the Olympics, when he somehow caught up with Alain Bernard, touched first by eight-hundredths of a second and kept Phelps on course to win a record eight golds.

“Relays are raced as a team,” Phelps said, “and I think all four guys swam a great race.”

Phelps was third when he passed off to Ryan Lochte, who hung tough against the hulking Bernard while surprising Russia surged into contention. Matt Grevers did his part on the third leg, and Adrian finished it off with fastest split of anyone to touch in 3:09.21.

Phelps pumped his fists on the pool deck, then leaned over to congratulate Adrian. Call him Lezak Jr.

“Coming in to this relay, to be honest, I felt like a child among men,” said Adrian, whose 100 was timed in 46.79 — nearly a full second faster than Phelps’ 47.78 opener. “All of these guys have made a great name for themselves, they’ve won individual medals at the Olympics, and they threw me on the last leg, so I had a little bit of pressure on myself.”

The French were the ones who cracked. The Russians touched second in 3:09.52, while France — which sent out four of the world’s fastest sprinters, at least on paper — were relegated to the bronze at 3:09.89.

“They’ve got the relay in their blood,” French coach Lionel Horter said of the Americans. “Even when they have a little problem, like for example, Phelps didn’t swim really well tonight, they still swam better than us.”

Phelps returned to the pool Monday morning for his first individual event, the 200 free. He put up the second-fastest time in the prelims, cruising into the evening semifinals.