Olympic bronze medallist Lutalo Muhammad secured Britain a -80kg berth for the Rio 2016 with victory in the World Taekwondo Grand Final.
Muhammad, 24, defeated former GB rival turned Moldovan fighter Aaron Cook, 7-3 in the final in Mexico City.
It guaranteed him a top-six world ranking at the season-ending event, meaning he joins Jade Jones in winning places for British fighters in Rio.
World champion Bianca Walkden will look to secure a +67kg berth on Sunday.
Muhammad was controversially chosen ahead of then world number one Cook for the London 2012 squad, but after a bitter legal battle his selection was approved by the British Olympic Association and he went on to secure bronze.
With Cook, also 24, subsequently defecting to the former Soviet state, Muhammad is now locked in a battle with world silver medallist Damon Sansum for Rio Olympic selection.
Sansum, who lost in the quarter-finals in Mexico, was leading the Olympic race until October, when Muhammad defeated him at the Manchester Taekwondo Grand Prix event.
A decision on which fighter will be selected for the Rio 2016 is not expected to be announced until closer to the Games.
Assuming world number two Walkden achieves enough points to secure her top-six finish, GB Taekwondo will look to attain a fourth place at the Games via the European Olympic qualification event in Istanbul in January.
Britain can only nominate one entrant for one division for that competition, with heavyweight Mahama Cho the favourite to be chosen.