The world number 140 was leading Italian Stefano Napolitano (28) 7-6(3) 6-6(6-5) when he hit a volley into the net on his second match point before launching the ball in frustration, catching chair umpire Ben Anderson in the face.

Polmans was immediately disqualified after the incident, which brought back memories of a similar one in 2017 when Denis Shapovalov inadvertently smashed a ball into the face of umpire Arnaud Gabas, leaving him with a fractured eye socket.

Media reports said Anderson was not seriously injured.

"An update from me - the umpire, Ben, has accepted my apology for my actions - he knows it was unintentional and I shanked the ball on the frame in frustration in the heat of the moment," Polmans wrote on social media platform X, formerly known as Twitter, on Wednesday.

"We both move on. It was a high pressure situation and I should have reacted better."

A win for him would have ensured a place in the main draw of an ATP 1000 event for the first time. Polmans will lose any prize money and ranking points picked up during the qualifying tournament.

The ATP has not said if he will face additional punishment.