Charlotte Henshaw overcame team-mate Emma Wiggs to win the women’s KL2 200 metres gold at the International Canoe Federation (ICF) Canoe Sprint and Paracanoe World Championships in Montemor.
The battle of the British athletes was one of three Paracanoe finals to take place on the second day of competition in Portugal.
Henshaw was able to celebrate a first world title, having switched to canoeing from swimming back in 2016.
She was able to clinch victory in a time of 52.627sec.
Henshaw ended just 0.775 in front of silver medallist Wiggs, the reigning Paralympic, world and European champion.
"I've been waiting for this for a long time, I never managed to do it as a swimmer, so this is pretty special," said Henshaw, who won Paralympic silver and bronze medals in swimming.
"I really think there is something to being comfortable with the water, and to understand and be confident with the movement through water and on water, and I think that has helped me out.
"There's an incredible team back in the UK who have guided me through that transition from swimming to kayaking, and it seems to be working."
Russia's Nadezda Andreeva completed the podium in a time of 56.412.
Former Para-skier Helene Ripa triumphed in the women's KL3 200m event, as the Swedish paddler achieved a time of 53.671.
She edged reigning world champion Amanda Reynolds of Australia, who finished second in 53.881.
Romania's Mihaela Lulea was third in 54.826.
Italy's Estaban Farias would successfully defend his world title, as he completed the men's KL1 200m in 49.796.
Paralympic silver medallist Robert Suba of Hungary was the runner-up in 50.606, with the podium rounded off by Brazil’s Luis Silva, who clocked 51.376.