RIO DE JANEIRO (AFP) - Britain smashed their own world record to win Olympic gold in the women's team pursuit in Rio on Saturday (Aug 13).

It was the third time in the space of 48 hours that the quartet of Katie Archibald, Laura Trott, Elinor Barker and Joanna Rowsell-Shand had set a new world mark in the 4km race.

The 2012 London Olympic champions beat world champions the US by more than two seconds in the final at the Olympic velodrome.

The US had briefly taken the world record in their morning semi-final but Britain, who first broke it on Thursday, improved on that in both their semi-final and final.

The Americans got off to a faster start in the final and were up by half a second after the opening 250-metre lap.

But the Brits went ahead definitely 1.5km into the race and from there they simply put the hammer down and pulled away to win in a time of 4min 10.236sec.

The US actually went almost as fast as their brief world record run of the morning but the Brits - who broke the record in each of their three runs during the Games - proved they had an extra gear.

For seven-time world champion Trott, it was a third Olympic crown having won gold in this event and the omnium in London four yeas ago.

Canada beat New Zealand to take the bronze medal.