Ailing world number three Alexander Zverev bows out of the ATP Indian Wells Masters in the third round against 55th-ranked Jan-Lennard. (Struff AFP/CLIVE BRUNSKILL) |
Struff, ranked 55th in the world, had never beaten his fellow German in four prior meetings.
But he was more than a match for the reigning ATP Finals champion, who said he has been battling illness for a week.
"That hasn't changed, unfortunately," said Zverev, who was coming off an appearance in the final at Acapulco where he lost to Australian Nick Kyrgios.
"I think I just got unlucky, I got a virus somewhere, and that's how it is," he said. "Now it's about getting healthy and about recovering and preparing myself for Miami, because Miami is the tournament I do well in, history-wise. Here I have always struggled."
Struff will fight for a quarter-final berth against 13th-seeded Canadian Milos Raonic, who rallied from 4-1 down in the third set to beat US qualifier Marcos Giron 4-6, 6-4, 6-4.
Struff beat Raonic in the first round in Dubai last month.
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