• Aryna Sabalenka used a phone to photograph a disputed ball mark during her Stuttgart Open match.
• Sabalenka received a warning for unsportsmanlike conduct but went on to win the match 6-4, 6-1.
• Jelena Ostapenko defeated Iga Swiatek, extending her winning streak against the world number two.

Aryna Sabalenka, the world number one, created a stir during her quarter-final match against Elise Mertens at the Stuttgart Open as she used a mobile phone to photograph a disputed ball mark. This incident occurred after umpire Miriam Bley refused her request for a second check on the call, which had given Mertens a break at 4-3 in the opening set. In response, Sabalenka borrowed a phone from a team member and took a picture, prompting mixed reactions from the crowd—both cheers and whistles—according to Channel News Asia.

Following the incident, Bley issued a warning to Sabalenka for unsportsmanlike conduct. Earlier, Sabalenka expressed her disbelief at the initial 'out' call and said that her request to check the mark herself was denied. However, she quickly refocused her efforts, breaking back immediately and eventually securing a dominant win at 6-4, 6-1. Sabalenka remarked post-match about the handshake she exchanged with Bley, stating, "there was a very interesting look and a very strong handshake," signifying lingering tensions, according to Reuters.

In another quarter-final match, Jelena Ostapenko continued to assert her dominance over Iga Swiatek by winning 6-3, 3-6, 6-2, thereby extending her winning streak against the Polish player to six matches. Ostapenko's performance in Stuttgart included 29 winners compared to Swiatek's 17 and showcased her ability to exploit weaknesses in Swiatek's game, particularly against her second serve, according to BBC.