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Michael Phelps got the U.S. Olympic swim trials off to the same start he did four years ago, uncorking a world record in the 400-meter individual medley on the opening night.

His riveting stroke-for-stroke duel with runner-up Ryan Lochte unleashed the crowd of 12,316 at the Qwest Center on Sunday night, and then Phelps thrilled them with the stunning time of 4 minutes 5.25 seconds.

At 4:06.08, Lochte also was under Phelps’ previous world record of 4:06.22, which was established last year.

The early crowd noise signaled to Phelps that “something special is going to happen.”

But he tried to temper his enthusiasm in the opening lap.

“I can’t get too excited; it’s only the first 50,” Phelps said.

“I definitely started the meet off on the right foot. I’m happy to go 4:05.”

That was only the beginning. There was another world record and one American record before the opening session concluded.

Katie Hoff established the world mark, going 4:31.12 in the 400 individual medley.

And Larsen Jensen set a U.S. record in the 400 freestyle in 3:43.53, edging Peter Vanderkaay’s 3:43.73. Both went under Vanderkaay’s American mark of 3:43.82, set in May at Santa Clara, Calif.

Said the 19-year-old Hoff:

“This one’s definitely a shock for me.”

That pretty much summed up an electric night of swimming.