Phelps, 27, is now the most decorated Olympian of all time with 19 medals.
US gymnasts McKayla Maroney, Kyla Ross, Alexandra Raisman, Gabrielle Douglas and Jordyn Wieber take the gold in the women's team gymnastics final, their first since 1996, as Russia and Romania get silver and bronze.
Team GB gymnast Jennifer Pinches receives commiseration after falling off the beam as teammates Beth Tweddle, Imogen Cairns, Rebecca Tunney and Hannah Whelan settle for sixth place.
The US's Travis Stevens defeats Brazil's Leandro Guilheiro at the quarter finals of the men's under-81kg judo.
And Team GB equestrian Zara Phillips, cheered on by the Duchess of Cambridge and Princes William and Harry, is presented with her silver medal for the team eventing by her mother Princess Anne.