Artur Beterbiev, the only current world champion boxer to have won all his professional fights by knockout, maintained his flawless record when he stopped Anthony Yarde in the eighth round of a thrilling world light-heavyweight title bout late on Saturday night.

The remorseless Beterbiev completed his 19th consecutive victory without needing to rely on the judges but Yarde fought magnificently, showing great skill and immense will as he pushed the Russian deep into punishing terrain. Their faces were cut, bleeding and swollen but, amid the brutality, the two men showed remarkable courage and resolve in equal measure.

As they began the decisive round, Yarde was ahead on two scorecards by margins of 68-65 and 67-66 while the third official had Beterbiev leading by just one point. Then, as he has done so often before, Beterbiev closed the show with unstoppable force to retain his IBF, WBC and WBO titles.

He nailed Yarde with two right hands that dropped the British challenger in his own corner. Beterbiev, who is a ruthless finisher, steamed in and was unloading heavy shots when Tunde Ajayi, Yarde’s trainer, waved the fight over. It was a compassionate and wise decision which matched the quality of an unforgettable contest.

The fight began with Beterbiev backing up Yarde in his distinctive marauding style but the 31-year-old Londoner displayed speed and mobility from the outset. Yarde also proved his nerve by snaking out slick counters and a jolting left hook. At the close of the opening round, the accuracy of his punching had marked up the reddened skin beneath Beterbiev’s left eye.

The left hook kept finding Beterbiev but the 38-year-old is a master at shutting down the distance and he pinned Yarde against the ropes in the second. He looked primed to cause his usual devastation but Yarde ducked under the scything punches and fired back, drawing roars from the partisan crowd. Yet he soon felt the impact of Beterbiev’s uppercuts which would land with sickening power throughout the rest of the fight.

The champion settled into his methodical rhythm in the third round and then came out for the fourth with bad intentions. Beterbiev’s intensity was suffocating and he hurt Yarde repeatedly. A small mouse was visible beneath Yarde’s right eye but he watched Beterbiev with hawkish vigilance.

Early in the fifth round, Yarde lost his gumshield for a second time. The referee Steve Gray’s insistence that it be cleaned before being slid back into his mouth at least offered fleeting respite from the growing menace of Beterbiev. But, just as Yarde shipped more damage, he cracked Beterbiev with a hard right. Sweat flew across the ring as, unusually, Beterbiev retreated. A left hook and then a shuddering right cross rocked Beterbiev in his own corner.

Yarde swarmed all over him and the supposedly impregnable Russian drew in a big gulp of breath. And then, like the great fighter he remains, Beterbiev launched a vicious counter-attack. Yarde was hurt to the body before his head was jolted by two monstrous uppercuts. He was in desperate need of the bell after an astonishing fifth round. Thousands of fans stood as one when the fighters turned to their corners, applause resounding in their honour.

A cut had opened up beneath Yarde’s right eye and he was soon under the blurring cosh as Beterbiev set about building an even more percussive momentum at the start of round six. Blood seeped down Yarde’s face but, undaunted, he mixed body shots with sharp combinations to the head. A matching gash above Beterbiev’s right eye confirmed their parity.

Yarde, lifted by the gory evidence of his success, stalked Beterbiev in an unexpected reversal of roles. Yet it was Beterbiev who shaded the round by shifting the momentum, again, as his right hook shook Yarde to the core. So much had been taken from both men, and we had just reached the supposed halfway point of a 12-round bout.

The home fighter came out for the seventh and was encouraged by another cut opening up under Beterbiev’s left eye. Yarde, fighting with surging conviction, was once more in the ascendancy. The champion was pinned in his own corner, just above my seat at ringside, as Yarde poured on the pressure. But then, with a masterful roll and swivel, Beterbiev spun Yarde round so that the challenger’s back was against the ropes.

Beterbiev let his fists fly in blurring flurries as one uppercut after another made Yarde’s head snap back and forth with alarming velocity. Thirty seconds were left in the round and, rather than buckling, Yarde fought back valiantly. He then uncorked an uppercut of his own which made Beterbiev wince in pain. As they traded in the centre of the ring, Beterbiev landed a right cross just before the bell. It had been another staggering round.

A tumultuous fight, full of so many twists and turns, would soon reach its culmination midway through the eighth round. A savage short right from Beterbiev stopped Yarde in his dazed tracks before an overhand right crashed home. Yarde went down heavily while, almost in relief, Beterbiev waved a black glove in the air. On his hands and knees, his contrasting white gloves pressed against the blue canvas, Yarde looked utterly lost.

He managed to rise at the count of seven. With blood running down his cheek, like an unbroken line of tears, he glanced briefly at his trainer before turning back to the heat and fury of Beterbiev. The referee urged him to approach and, slowly, Yarde walked towards him. Beterbiev needed no further invitation. He unfurled another dark train of punches – only for the fight to be brought to a merciful end by Yarde’s concerned trainer.

Beterbiev raised his arms in triumph before also sinking to the canvas. It was his turn to be on his hands and knees as, with his head bowed, this devout Muslim gave thanks for the hardest victory of his career. Beterbiev’s cornermen turned to a few of us at ringside to express their admiration for Yarde and to confirm the severity of the challenge their man had just endured. They shook their heads with something like awe.

Boxing is a corrupt and dirty business, as shameless as it is lost, but it also retains the capacity to produce fights such as this epic contest. This was a night that will live long in the memory – and belong forever to both extraordinary fighters.