Record-breaking Michael Phelps extended his tally to 21 Olympic gold medals as he won individual and team titles on day four at Rio 2016.

The American, 31, comprehensively beat defending champion Chad le Clos in the 200m butterfly.

The most decorated Olympian of all time then helped the US win the men's 4x200m freestyle relay by a wide margin.

British quartet Stephen Milne, Duncan Scott, Dan Wallace and James Guy won the silver medal.

Phelps began the evening by avenging 24-year-old Le Clos' victory over him at London 2012.

He cruised to victory in one minute 53.36 seconds as the South African only managed to finish fourth.

Japan's Masato Sakai and Hungary's Tamas Kenderesi overtook Le Clos in the final 50 metres to take the silver and bronze medals respectively.

Phelps and Le Clos meet again in another latest instalment of their duel when they compete in the 100m butterfly later this week.

But reclaiming the individual 200m butterfly title was Phelps' main target in Rio following his dramatic defeat in London four years ago.

That final was supposed to be his farewell to the sport, having already announced his intention to retire after the Games.

He came out of retirement in 2014.

Phelps has won more than twice as many Olympic gold medals as the athlete second on the list, former Soviet gymnast Larisa Latynina (nine).

Phelps returned to the pool just over an hour after his individual triumph to compete in the relay alongside US team-mates Conor Dwyer, Francis Haas and Ryan Lochte.

The defending Olympic champions lost to Britain at the 2015 World Championships, but led from the early stages to win by 2.47 seconds and retain their crown.