Alice Dearing produced a brilliant swim at the Olympic qualifier in Setubal to earn Team GB a quota place in the 10km marathon swimming event.
The 24-year-old finished fourth to secure the quota spot, with the top nine finishers earning a position at the competition in Portugal.
Only one swimmer per country could earn a quota spot, with Birmingham ace Dearing and Danielle Huskisson both vying for a spot.
The pair battled hard through the early stages of the race, staying in touch with the lead group as swimmers fell off the pace.
And Dearing was able to make the decisive break just after the bell, pulling clear in a leading group of five.
She eventually came home in fourth, with Huskisson ending up in 13th spot in the 47-strong field.
The competition will continue on Sunday with the men’s 10km event where Hector Pardoe and Tobias Robinson looking to secure a quota spot.