Michael Phelps has won a 21st Olympic gold medal after a very productive end to day four in Rio.
The Baltimore bullet claimed a dominant victory in the 200 metres butterfly before then going on to anchor the US team which comfortably won the 200m freestyle relay.
South African Chad Le Clos shocked Phelps by winning gold ahead of his idol, in Phelps' signature event, at the London 2012 Games.
Phelps had won the title at the 2004 and 2008 Olympics and reclaimed it with a block to wall victory in one minute 53.36 seconds on Tuesday.
Masato Sakai of Japan threatened to come from behind to upset the American, finishing four one-hundredths of a second behind in second.
Hungary's Tamas Kenderesi took bronze in 1:53.62 as Le Clos finished outside the medals in fourth in 1:54.06.
Both Le Clos' parents - mum Geraldine and father Bert, whose exuberant celebrations captured the public's imagination four years ago - have cancer.
And there was no emotional victory for the South African this time round as Phelps reigned supreme.
Phelps was drafted into the United States' relay team following the afternoon heats and produced a strong anchoring leg after being handed a dominant lead.
James Guy of Great Britain produced a strong final leg to secure silver, perhaps making up for his own fourth place finish over this distance, while Japan held off Russia for bronze.
Phelps already had one gold from Rio - his 19th, which came in the 4x100m freestyle relay on Saturday.
