Swimming: Phelps to defend 100m butterfly title in Rio after winning his last US race

Michael Phelps smiling during the medal ceremony for the Men's 100-metre butterfly  in Omaha. Nebraska, on July 2, 2016.
Michael Phelps smiling during the medal ceremony for the Men's 100-metre butterfly in Omaha. Nebraska, on July 2, 2016. PHOTO: AFP/GETTY IMAGES

OMAHA, NEBRASKA (REUTERS) - Michael Phelps gave the home fans one last thrill when he touched first in the 100m butterfly at the US Olympic trials on Saturday in his final race in an American pool.

The world record holder and three-time Olympic champion in the event, Phelps charged to the wall to the roar of a capacity crowd in a time of exactly 51 seconds, just ahead of Tom Shields.

With his trials over, Phelps heads to Rio for what he says will be his fifth and final Games having qualified in three events; the 100m and 200m butterfly and 200m individual medley, ready to add to his staggering record total of 22 Olympic medals.

"Bob (coach Bowman) asked me what the game plan was tonight and I said, 'I don't want to lose my last race on American soil'," said Phelps. "There's been a lot of history here and 51 (seconds) is OK but it's going to take more than that to win a gold medal."

Phelps began his final US race from an unfamiliar spot, lining up in lane seven.

But everything else was vintage Phelps as he powered into the lead over the final 50m.

When he hit the wall, the 31-year-old immediately turned and looked up at the clock, clenching his fist and punching the water, underscoring how much the win meant to him.

As he climbed out of the pool the crowd stood and cheered the 18-time Olympic champion, who raised both hands in the air, soaking up the moment as he turned to all for corners of the arena taking a final bow.

While Phelps came through with the victory almost everyone at the packed CenturyLink Center wanted to see, Katie Ledecky cruised to a commanding win in the women's 800m freestyle but could not deliver the first world record at the trials that many expected.

After clocking the third-fastest time ever in the event during Thursday's preliminaries, the Olympic and world champion looked primed to eclipse her own world mark of 8:06.81.

Ledecky went out in world record pace but faded on the back half and finished in 8:10.32, a comfortable 10 seconds clear of her nearest challenger Leah Smith.

Like Phelps, Ledecky will also go to Rio having qualified for three events, the 200m, 400m and 800m free. She hopes to become the first swimmer since 1968 to complete the Olympic gold medal distance hat-trick.