Tien stunned Daniil Medvedev in Melbourne. A teenager notched another high-profile win in Acapulco this week, toppling world no. 2 Alexander Zverev in the second round. Thus, Lear

Alexander's latest setback came against the 19-year-old Learnen Tien in the second round in Acapulco. A teenager ousted the Australian Open finalist 6-3, 6-4 in an hour and 28 minutes for his second top-5 victory of the season.

Zverev, the top seed at the Acapulco Open, went down 6-3 6-4 to the 19-year-old American on Wednesday. Tien, who claimed a big win over Daniil Medvedev en route to reaching the fourth round at the Australian Open in January, came from 1-4 down to win the second set – and the match – by reeling off five straight games.

Learner Tien, a 19-year-old from California, took down top-seeded Alexander Zverev 6-3, 6-4 on Wednesday to advance to the Acapulco Open quarterfinals.

Zverev is one of several top players in Acapulco who was reportedly affected by stomach issues or food poisoning, with the draw taking a big hit on Wednesday. Casper Ruud and Tomm