And that surpassed the previous best Olympic Grand Prix score of 78.20 per cent, set by Sprehe's countrywoman Ulla Salzgeber at Athens 2004.
The Netherlands' second team rider, Edward Gal, gave his country the strong score it needed, posting 75.28 per cent on Undercover.
Gal's medal-laden partnership with his previous horse, Totilas - it is now ridden by Germany's Matthias Rath - was the greatest Dressage has seen.
But Gal showed he has lost none of his quality by conjuring a quality test out of his new partner.
'I hope we (Netherlands) will get a medal - but I don't know which colour yet,' Gal said.