The world number two battled past Spain's Alejandro Davidovich Fokina, winning 2-6, 7-6 (7-3), 7-6 (7-0) to move into the last 16. However, his victory was overshadowed by controversy in the second set. Zverev was convinced that a backhand shot from Davidovich Fokina in the 10th game had landed wide, but the electronic system ruled it in.
Frustrated, Zverev argued with umpire Mohamed Lahyani, claiming there was a "malfunction in the system." After his protests were dismissed, he took matters into his own hands by retrieving his phone from his bag and photographing the ball mark on the clay. His actions earned him a warning for unsportsmanlike conduct. Nevertheless, the 28-year-old managed to regain his composure and sealed the match by winning consecutive tie-breaks.
While other surfaces have embraced electronic line-calling, clay-court tournaments traditionally relied on line judges or umpires physically checking ball marks during disputes. This season, however, line judges have been removed from all ATP Tour events and many WTA tournaments, bringing clay into the digital era. Despite these changes, the French Open, which starts next month, will continue to use line judges.
Zverev's incident is the latest controversy linked to electronic calls on clay. Earlier this month, world number one Aryna Sabalenka received a warning for photographing a ball mark during her match in Stuttgart, and former Grand Slam champion Victoria Azarenka recently posted an image highlighting a questionable call in Madrid on social media.
Meanwhile, defending men's champion Andrey Rublev was knocked out in Madrid, losing 6-4, 0-6, 6-4 to Alexander Bublik. This defeat means Rublev will drop out of the world's top 15 rankings.
In the women's draw, top seed Sabalenka recovered from a slow start to defeat Elise Mertens 3-6, 6-2, 6-1. However, there were major upsets elsewhere. Third seed Jessica Pegula was beaten 6-3, 6-2 by Japan's Moyuka Uchijima, and sixth seed Jasmine Paolini fell to Maria Sakkari of Greece, losing 6-2, 6-1.
