Miller (17-2, 3 KOs) and Powar (14-1-1, 1 KO) boxed on the undercard of the WBC light heavyweight title fight between Willy Hutchinson and Joshua Buatsi at Manchester’s AO Arena. 

A huge swelling began to form on the left side of Miller’s forehead after an accidental clash of heads in the 6th round of a back-and-forth battle.

Although it didn’t slow the 29-year-old from Ashton down, the injury quickly worsened. 

A ringside doctor inspected the injury during the 9th round and allowed Miller to continue but by the 10th round, the swelling had moved around his forehead and another huge lump had formed on the right side of his head. The doctor immediately stopped the fight after seeing how the injury had worsened.

Because the injury was caused by an accidental foul, the fight went to the scorecards and Powar, 24, was awarded a unanimous technical decision.

Images of the alarming injury have captured attention outside of the boxing world, and Miller’s manager, Kevin Maree, took to social media to provide an update on the former British champion’s condition.

“An accidental clash of heads caused significant swelling to the top of his head. Zak was thoroughly assessed by the medical team at the venue before being taken straight to hospital for further checks.

“He was kept in hospital for observation and underwent a full assessment. Thankfully, the medical team are happy with how he is doing, and we expect him to be back to his handsome self very soon.

“Zak really is a special person, and the sheer number of people asking about him and checking on his wellbeing last night shows just how much he means to so many. It’s a real testament to the person he is, both inside and outside the ring.

“Last night was a stark reminder of just how tough and unforgiving this sport can be. Every single fighter who steps through those ropes puts themselves on the line and deserves the utmost respect.

"We would like to thank everyone who has shown their concern and sent their best wishes.

"Wishing Zak a speedy recovery.”