Michael Phelps barely qualified in the 400-meter individual medley on the opening day of Olympic swimming, squeaking into the final by seven-hundredths of a second on Saturday.
"That one didn't feel too good," he said.
The two-time defending Olympic champion won his heat in 4 minutes, 13.33 seconds with a time that was well off his world record of 4:03.84 set four years ago in Beijing, when Phelps won a record eight gold medals.
But it was only good enough to secure the last spot in the evening final, when Phelps will swim in lane one instead of the middle of the pool.
"The only thing that matters is just getting a spot in," he said.
"You can't win the gold medal from the morning."
Kosuke Hagino of Japan led the way in 4:10.01. Chad le Clos of South Africa was second at 4:12.24, and American Ryan Lochte advanced in third at 4:12.35.
Phelps' time was just fast enough to keep Laszlo Cseh of Hungary, the silver medalist in Beijing, out of the final. Cseh was ninth overall after leading Phelps during their heat. Phelps closed on the last lap of freestyle to beat him to the wall.
Phelps' slow time in an event he had vowed not to swim again after Beijing took some of the luster off what was expected to be a showdown between him and Lochte for gold.
Lochte, the bronze medalist in Beijing, has won the 400 IM at the last two world championships.
"You can't count him out," Lochte saiad. "Even though he just squeaked in eighth, he's a racer. We're going to do everything we can to go 1-2 tonight."
Photograph: David J. Phillip / AP