Aryna Sabalenka was involved in a tense argument with her chair umpire during Saturday’s Stuttgart Open win against Elise Mertens.

Aryna Sabalenka took a photo of the court. (Image: The Tennis Channel)

Aryna Sabalenka booked her spot in the Stuttgart Open semi-finals by cruising past Elise Mertens in a 6-4 6-1 victory on Saturday. However, the world No. 1’s triumph didn’t come without controversy after a disagreement over a line call sparked a spat involving chair umpire Miriam Bley.

Sabalenka outclassed Mertens in their 11th meeting after facing a prolonged wait to start her campaign in Germany. She was slated to face Anastasia Potapova in the second round before the Russian’s withdrawal, yet that didn’t prevent her from displaying dominance on Centre Court. But there was an edgy moment between Sabalenka and the chair umpire as the pair argued over a line call the former believed was incorrect.

The 26-year-old asked Bley to review the mark of a ball after the umpire called her shot “out” while she was break point down.

At the changeover, while 4-3 down, Sabalenka then took it upon herself to collect a phone from her team and take a photo of the mark in a clear show of disdain over Bley’s call.

Bley handed her a warning for unsportsmanlike conduct, and, according to Sabalenka, there was a hint of ill feeling that lingered after she sealed progression into the final four.

There were no issues from there on in as she soared to victory, and after the match, she admitted that she could tell the chair umpire was annoyed by her actions.

Aryna Sabalenka is into the Stuttgart Open semi-finals. (Image: Getty)

“I felt how the referee was p*****, probably by the picture I took,” Sabalenka explained in the post-match interview.

“When I gave her a handshake, there was a very interesting look and a very strong handshake. I’ve never had it before.”

Sabalenka landed a further jab on Bley when asked whether she returned the favour and squeezed her hand back.

She replied: “No, it’s okay, why would I play this game with someone like her? It’s okay.”

Sabalenka will face Jasmine Paolini for a place in the Stuttgart Open final after the Italian beat Coco Gauff 6-4 6-3 later in the day.

She is looking to continue a productive clay court season so far after beating Jessica Pegula in the Miami Open final at the end of March.

Before her triumphant campaign in Miami, Sabalenka reached the Indian Wells final before falling to Mirra Andreeva in three sets in the showpiece match.

In the other Stuttgart Open semi-final, Ekaterina Alexandrova will face Jelena Ostapenko before Sabalenka and Paolini’s clash.