(Reuters) - Casper Ruud was one of three top seeds to exit the Mexican Open on Wednesday due to the effects of a stomach bug, while both Alexander Zverev and Ben Shelton suffered early defeats at the ATP 500 tournament in Acapulco.
Last year's runner-up and second seed Ruud pulled out shortly before his match against Rodrigo Pacheco Mendez, sending the local favourite through to the quarter-finals.
"I was hoping to overcome this stomach illness that showed up yesterday," Ruud said on Instagram, adding that he had tried everything he could until the last moment to be able to play.
"Hoping to come back stronger in a couple of days and come back here to Mexico next year."
Reuters has contacted tournament organisers for comment.
American third seed Tommy Paul withdrew with a similar problem ahead of his meeting with countryman Marcos Giron, who now takes on Denis Shapovalov after the Canadian beat Alex Michelsen 6-4 6-3.
Michelsen also needed medical attention during that match.
Fourth seed Holger Rune was able to take to the court against Brandon Nakashima but threw in the towel while trailing 3-0 in the opening set.
"Furious and so sad at the same time. Had food poisoning and was unable to play today," Rune said on X.
"One of my favourite places is Mexico and I love this tournament. Absolutely not the way I wanted it to end."
Top seeded German Zverev was well below his best in a 6-3 6-4 defeat by American teenager Learner Tien, while fifth seed Shelton crashed out 7-6(3) 6-3 to David Goffin.
In a late contest, Alejandro Davidovich Fokina sent seventh seed Frances Tiafoe packing 6-3 6-7(6) 6-3.
(Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Peter Rutherford)
