Britain’s 18-year-old Emma Raducanu became the first qualifier to capture a Grand Slam title by defeating Canada’s 19-year-old Leylah Fernandez in the US Open women’s final today. Raducanu, ranked 150th, was the first British woman in 44 years to win a Slam crown after dispatching 73rd-ranked left-hander Fernandez 6-4, 6-3. Not since Virginia Wade in…