It was the 19-year-old's second career win over a top-five player, after he defeated Daniil Medvedev in the Australian Open second round in January.

American Learner Tien knocked out No. 1 seed Alexander Zverev, while three players exited citing stomach issues.

The Mexican Open faces unexpected challenges as a stomach bug sidelines top-seeded players, including Casper Ruud, Tommy Paul ...

World number two Alexander Zverev suffers a shock early exit from the Mexican Open with a straight-set defeat against teenage qualifier Learner Tien.

Players dropping like flies today at ATP 500 Acapulco today. After Tommy Paul withdrew just before his match with stomach ...

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 ...

Tallon Griekspoor rallied to defeat defending champion Ugo Humbert of France 4-6, 6-3, 6-2 and reach the quarterfinals at the ...

Top seed Alexander Zverev and fifth seed Ben Shelton were eliminated inside Arena GNP Seguros. Zverev went down to 19-year-old qualifier Learner Tien, 6-3, 6-4, while Shelton was on the receiving end ...

With Jannik Sinner serving a doping suspension, and Taylor Fritz's status uncertain because of an injured abdominal muscle, ...

Casper Ruud reached an ATP 500 final this year already (Dallas) and looks primed for a deep run at this Acapulco event as ...

First-round action at the Mexican Open in Acapulco promises a spate of high-quality matches. Former runner-up Tommy Paul ...