Michael Phelps has added one final medal to his Olympic tally, taking gold with Team USA in the men's 4x100m medley relay.

The most decorated Olympian of all time came out of retirement to compete in Rio de Janeiro and extended his medal count to 28, including 23 golds, three silvers and two bronze.

Team USA finished the relay with a final time of 3:27.95, including a third-leg contribution of 50.33s from Phelps before teammate Nathan Adrian brought home the win in 46.74s.

Team GB - Chris Walker-Hebborn, Adam Peaty, James Guy and Duncan Scott - picked up the silver medal with a time of 3:29.24 to complete their most successful ever Olympics in the pool, while bronze went the way of Australia after China were disqualified.

Speaking on the eve of his final Olympic event yesterday, Phelps insisted that "this is it" when asked if he could compete in the 2020 Olympics.