Swindon's Jazz Carlin has won silver in the women's 400m freestyle.
The 25-year-old, who trains at Bath University, had been coy about her expectations for Rio in the build up, but gave a strong performance in the pool.
Her success - coming in after Kathleen Ledecky of the US, who won gold - came just moments after Adam Peaty took Team GB's first gold in the men's 100m breaststroke.
Jazz says she was gobsmacked.
It is particularly poignant as Jazz was tipped for a medal at London 2012 but was struck down by glandular fever.
Jazz took to Twitter earlier today to express her joy