Michael Phelps added further gloss to his incredible career after the American notched his 20th Olympic medal and 16th gold medal with victory in the 200 meter individual medley, in the process, knocking back rival and friend Ryan Lochte into second place.
Leading from the start, Phelps, who was under world record pace for most of the race, finished in a time of 1:54.27, .027 slower than the world mark of Lochte. Phelps' American teammate, however, had to settle for silver, while Laszlo Cseh of Hungary took bronze.
"Somebody told me that, with 25 meters left, I was under world record pace, so it's a little frustrating not to get that," said Phelps, who became the first man to defend an Olympic swimming title twice having won the event in Athens and Beijing.
"But to win a gold medal and be the first to three successive titles is something pretty special and something I'm pretty happy for.
"The President of the United States Barack Obama called me on Wednesday," Phelps told BBC Sport. "It was pretty cool.
"Someone called me up and asked me to hold on as they had the president waiting to speak to me. He told me that everyone is supporting me. It was very special and he said to say 'hi' to my mum."
Another American Rebecca Soni beat her own world record to win the gold in the 200 meter breaststroke. Soni finished in a time of 2 minutes, 19.59 seconds, becoming the first woman to break the 2:20.00 mark.
"I've been chasing that for years, that was for my old coach Tom who told me I was going to go that fast," the delighted 25-year-old said.
"I kept it to myself as a secret goal, but that was for Tom. He believed in me more than any coach I've known, but as a young kid he was someone I looked up to and he kept pushing me."
Japan's Satomi Suzuki won silver while Russia's Iuliia Efimova took bronze.
