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Video - Third dressage gold for van Grunsven
Anky van Grunsven of the Netherlands scored an overall 78.680% to win a record third successive Olympic gold medal in the individual dressage.
Van Grunsven, riding Salinero, edged out German pair Isabel Werth (76.650%) and Heikke Kemmer (74.455%).
The 40-year-old produced a stunning display to deny her great rival Werth.
Britain's Emma Hindle ended in seventh with an overall score of 72.345%, a new British record for the individual dressage at an Olympic Games.
The 33-year-old, riding Lancet, underwent an operation to remove a tumour in late June and was unable to ride until two weeks before the start of the competition.
But her score of 74.250% on the day briefly saw her top the medal table before Van Grunsven, Werth (on Satchmo) and Kemmer (on Bonaparte) were among those to usurp her.
"I'm really happy," said Hindle. "(Lancet) normally gets a little afraid but he has worked for me all through the competition and I can't ask for any more from him.
"Normally I don't do well in freestyle and this is definitely one of the best we have done."
"It is amazing because two weeks before I came out here I couldn't ride as I had only recently got out of hospital after being operated on for a tumour.
"But the British team got me prepared and stood by me and I had everyone coming to help me. It really means a great deal and makes you proud to be British."
Werth's performance was marred by an expensive mistake less than half-way through her performance when Satchmo stopped as she appeared to lose control of him.
The Atlanta 1996 champion said later that had Satchmo stayed within her control throughout, "it would be very exciting between Anky and me".
The horse had shied violently during her first round performance on Saturday, costing her around 8%, as her scores per movement had been sensational until that moment.
Van Grunsven has suggested this will probably be her last Olympics as she is planning to retire to spend time with her two children.