Martina Navratilova, Boris Becker & Donna Vekic send strongly-worded messages to defend Alexander Zverev after Madrid controversy 

Boris Becker, Martina Navratilova, and Donna Vekic supported German Alexander Zverev, who shared a picture of the ball mark to prove that electronic line calling during the Madrid Open third round was incorrect. Zverev went against Alejandro Davidovich Fokina in the round, where he argued over a point wrongly awarded to the latter.

Alexander Zverev entered the Masters 1000 event as the top-seeded player. He trounced Roberto Bautista Agut in the opening round and advanced to the third round against Spaniard Alejandro Davidovich Fokina. Though he had a slow start, losing the set 2-6, the German picked up pace despite being constantly challenged by the opponent.

It was when the players changed sides and the first point was awarded to Davidovich for his sliced backhand shot. The German protested and expressed doubts over the accuracy of the electronic line calling system. He got into a feud with chair umpire, Mohamed Lahyani, and even suggested that he step down for a look at the ball mark.

After back-and-forth with Layhani, Alexander Zverev brought out his phone and snapped the ball mark on the clay court, proving that it was a clear out.

"Just gonna leave this one here. This was called in. Interesting call"

Former player and tennis commentator Boris Becker sided with Zverev and wrote:

"clearly OUT"

Former World No. 1 Martina Navratilova joined forces and wrote:

"It’s definitely out no matter which angle you look from. And there is no other mark- this particular setup needs to be improved… something is way off"

Croatian player Donna Vekic supported the German, writing:

"So crazy that umpires are not able to overrule this ! Insanity"

Zverev concluded the round with a 2-6 7-6 (3) 7-6 (0) victory over Davidovich, but was warned for unsportsmanlike conduct since he took a picture. He will now aim to bag his third Madrid Open title.

Boris Becker spilled beans about his relationship with fellow German Alexander Zverev

Alexander Zverev at the ATP Tour - Munich... - (Source: Getty)

Boris Becker has been supportive of Zverev throughout the latter's tennis career. He even guided his younger counterpart several times and accompanied him to his training sessions. Shedding light on his bond with Alexander Zverev, Becker said:

"Sascha [Zverev] is a bit like a sports foster son. We are actually in regular exchange, he can call me day and night if he has a question, and then maybe I can answer them on the phone, or I can come to the training live.But what these conversations involve, you have to understand, that’s private.” (The Tennis Gazette)

He further shared that Zverev's strengths and weaknesses are at his fingertips.

"I know almost everything about his strengths and weaknesses. This is also important, because otherwise I can’t help him."

Though the 57-year-old wishes for a Grand Slam victory for Zverev, and also clarified why he wouldn't be the latter's coach.

"I won’t be a coach. That will always remain his father. He is now emotionally in a very exciting phase, because he wants to achieve something he has never achieved before. That means Grand Slam victory, and that of course also means the number one in the world."

Zverev won 24 ATP Tour titles in singles and two doubles titles in his storied career.