[2] With the moral support of both her father and boyfriend, in the winter of 1929/1930, she eventually decided to formally enter the 1930 race.

[2] The 9th edition of the race for 1930 attracted a record entry list of 101 aircraft, to be piloted by many notable aviators including several former King's Cup winners, and the Schneider trophy winner of 1929 Richard Waghorn, and Augustus Orlebar who had set the world speed record with 357.7 mph (575.7 km/h) flying a Supermarine S.6.

[5] On 4 July 1930, she arrived at London Air Park, Hanworth, with her companion Ron Adams, but she was denied a room at the local aero club where a social pre-race event was taking place, and instead stayed elsewhere.

[2] She chose to fly over the Woodhead Pass crossing the Pennines mountain range towards Cramlington, where she was received with the news she was then in the lead.

[2] She crossed the finishing line at Hanworth in her Avro Avian III G-EBVZ at 6:16 pm, followed ten minutes later by A.S. Butler (Chairman of de Havilland Aircraft Co), flying a DH.60M Moth G-AAXG into second place.

[3] With an average speed of just over 100 miles per hour (160 km/h), Winifred Brown was the first woman to win the King's Cup air race.

[12] After her victory in one of the most prestigious air races in the United Kingdom, she was welcomed in several official ceremonies and events including a reception in the House of Commons.

[2] After flying, Brown went to South America where she explored the length of the River Amazon in a ship and canoe.

[15] From 1976, Brown lived on Seaway, a motor yacht bought by her son Tony, moving between Lymington and Brighton.