John Gosden’s filly had won her only previous start at Yarmouth and was sent off a 100-30 chance in what looked a strong Group Two.
The Clarehaven handler was winning the race for a fifth time, having last prevailed with Rainbow View in 2008 in the same George Strawbridge silks.
A sister to the Group One winner Journey, Indigo Girl broke awkwardly from the stalls which meant she was at the back of the field early.
However, she made eyecatching progress up the stands side with three furlongs to run and was soon challenging Dubai Fountain for the lead.
Her lack of experience told as she then jinked to her left, while favourite Zabeel Queen on the far side was also running off a straight line.
However, once Frankie Dettori was able to get her straightened up to a certain degree, the daughter of Dubawi went on to win by three-quarters of a length from Dubai Fountain, with Zabeel Queen a length away in third.
It was a quick double for Gosden and Dettori after Logician’s stroll earlier on the card and the winner was introduced into the 1000 Guineas betting at 14-1 by Paddy Power.
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