Stefanos Tsitsipas repeatedly failed to capitalise on his chances as the second seed went down to Polish outsider Hurbert Hurkacz 2-6, 6-3, 6-4 to reach the semi-finals of the Miami Masters on Thursday.
Tsitsipas joined tournament top seed Daniil Medvedev, who was dumped out 24 hours earlier.
Hurkacz seized his opportunities to claim victory over his Greek opponent for only the second time in their series. Tsitsipas now leads their series 6-2.
The seed had a chance to head towards a possible straight-sets victory and wrap up early but was unable to get the job done.
Leading 6-2, 2-0 40-15, Tsisipas hit a rough spot, losing eight of the next 10 points as No. 37 Hurkacz began his fightback which eventually ended after almost two and a half hours.
In the third set, a break at 2-all as Tsitsipas missed on a smash paved the way for the eventual Polish victory and a semi-final date with the winner from Seb Korda and fourth seed Andrey Rublev.
Late in the match, a frustrated Tsitsipas got into a row with the chair umpire for taking too long to change a shirt during a changeover.
The contest was the sixth straight in the series where a third set was required.
Tsitsipas was playing a seventh Masters 1000 quarter-finals and is now 5-2 at that level.
Main photo:- Hubert Hurkacz wins Miami Masters quarter final by ©ATPTour.com/Pete Staples