Daniil Medvedev, last year’s Wimbledon semifinalist, suffered his first loss of the grasscourt season in the Halle Open. He was defeated by Zhang Zhizhen in a thrilling three-set match, marking the Chinese player’s first win over a top-five opponent on grass. Alexander Zverev, the German world number four, advanced to the quarterfinals after a hard-fought victory against Lorenzo Sonego.