Novak Djokovic's pursuit of a record seventh Miami Open ATP title ended in dramatic fashion on Tuesday as Roberto Bautista Agut superbly recovered from a first set destruction to win 1-6, 7-5, 6-3 and book a place in the quarter-finals.
And the top seeds kept falling as women's world number two Petra Kvitova slumped to a surprise 7-6 (8/6), 3-6, 6-2 defeat to Australian Ashleigh Barty.
Bautista Agut, 30, may have beaten Djokovic on the way to winning the title in Doha earlier this year but 15-time Grand Slam champion Djokovic started like a train in this last 16 encounter before being amazingly reined back in.
After just 25 minutes, Djokovic was 5-0 ahead and on cruise control, Bautista Agut severely struggling to keep the Serbian at bay. A short rain delay late in the second set allowed Bautista Agut to regroup, however.
He returned a completely different player and at the end of an absorbing two hours and 29 minutes, it was the number 22 seed who will now meet defending champion John Isner for a place in the semi-finals.
With Roger Federer's match with Daniil Medvedev postponed until Wednesday after a spell of heavy rain forced tournament officials into a reshuffle, all the focus remained on Djokovic's shock exit.
The reigning Wimbledon, US Open and Australian Open champion left court and headed straight to a press conference to try and explain this most remarkable of turnarounds at Hard Rock Stadium.
Djokovic, who also hinted his vociferous involvement in ATP tennis politics which saw President Chris Kermode ousted this month may have affected his focus, was initially consistent with his serve during the opening set. He mixed up is shots superbly, blending power and subtlety to keep his opponent guessing.
However, a drop in Djokovic's level coupled with a rise in Bautista Agut's aggression saw a complete reversal in fortunes after a 30 minute weather delay. The Spaniard grabbed two set points, the second of which was taken when the Serbian netted a forehand.
Bautista Agut broke again for 3-1 in the third following an uncharacteristic double fault and although Djokovic hit back in the very next game, the Spaniard again took advantage of his opponent's faltering serve to move within two games of victory.