Only two seeds remain in the field after a chaotic day at the Heineken Open tennis tournament in Auckland.
The highest ranked player remaining in the field, world number 13, Ernests Gulbis, was beaten by the Czech qualifier, Jiri Vesely, 6-2 3-6 6-1 on centre court.
The world number 63 called the win over the Latvian the biggest of his career and he will meet the American, Donald Young, in the quarter-finals.
Gulbis' departure follows the withdrawal of the Spanish fifth seed, Tommy Robredo, and the retirement due to illness of his compatriot and world number 15, Roberto Bautista Agut.
The exodus comes after the previous withdrawals of John Isner, David Ferrer and Gael Monfils, leaving just one of the seven top 20 players who signed up for the tournament in the draw at the quarter-final stage.
That's the South African, Kevin Anderson, who will meet the only other remaining seed, Steve Johnson, in the quarter-finals.
Meanwhile, the New Zealand wildcard pairing of Artem Sitak and Michael Venus won their first round doubles match, beating the third seeds from Colombia Juan Sebastian Cabal and Robert Farah.