Phelps competed in the 4×200-metre freestyle relay with his fellow teammates Ryan Lochte, Conor Dwyer and Ricky Berens and swam his way into the record books as they beat out France by three seconds. China came in third to win the bronze medal.
This latest win makes Phelps the first Olympic contestant to have 19 medals to his name, 15 of which were awarded for first place. The former record holder was former Soviet gymnast Larisa Latynina, who won 18 medals.
Earlier today, Phelps won silver in the 4×100-meter freestyle relay. The 27-year-old swimmer has two more chances as he competes in the 100-meter butterfly and 200-meter individual medley finals.
Phelps has previously insisted the London 2012 Games will be his last.
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