WATCH: Bloodied Russian warrior maintains unique KO record with brutal shot

Artur Beterbiev maintained his unique 100% knockout record and retained both of his light heavyweight titles with victory over Marcus Browne on Friday evening.

Improving to 17-0, the Dagestani native saw off Browne at the Bell Centre in his adopted city of Montreal.

Before the bout got underway, there was controversy when organizers played a tune with the words to the old USSR anthem and not its modern-day Russian successor.

This was not enough to throw Beterbiev off, though, with the WBC and IBF king delivering a ninth-round stoppage and remaining the only reigning world champion with a perfect record of finishing each fight by TKO/KO. 

But the 36-year-old had to work for his money, and was bloodied by his American foe.

This happened after an accidental clash of heads in the fourth round, which opened a deep gash on the Russian's forehead and cut the outside of Browne's eye.

Beterbiev was told by the doctor at the beginning of the following round that the fight would only go on one more, which triggered urgency from the man tipped to take on pound-for-pound great Saul 'Canelo' Alvarez.

Despite the warning, the fight was allowed to continue even beyond Browne being knocked down in the seventh. 

By the ninth, though, Browne, now 24-2, was unable to recover after being grounded by a brutal body shot.

As quipped by the Top Rank social media account, the blood only made Beterbiev hungrier.

In his post-fight interview there were no call-outs for the likes of Alvarez or Beterbiev's compatriot Dmitry Bivol, who is the WBA champion, making a unification bout between the pair possible. 

Rather than being impressed by Beterbiev soldiering on and getting the win, some fans and pundits such as former super middleweight ruler Andre Ward suggested that Father Time might be catching up with him. 

"This dude looked slow against an opponent that he should have taken out quick," said one punter.

Yet that individual was asked if this was the first time he had seen Beterbiev considering the majority of his finishes lately have come in the mid-to-late rounds.  

"Beterbiev looks very beatable tonight," Ward had said during the fight and was told: "You looked beatable against [Sergey] Kovalev" in reference to a controversial first showdown between the two in 2016 that the 'Son of God' won by unanimous decision where many felt he had lost. 

"I don’t know if it’s his age or the layoffs," Ward, who beat Kovalev by an eighth round TKO in their sequel, added later.

"But Beterbiev saw a lot of shots that he could not get off tonight. You will see more guys trying to fight him now," he predicted.

Accused of waiting for Gennady Golovkin to age, and similarly being gifted a controversial draw before beating the Kazakhstani at the second time of asking, one of these guys could be Alvarez.

First up for the fighter many deem to be the best on the planet, however, is meant to be a bid to becoming a five-weight champion by taking on WBC cruiserweight ruler Ilunga Makabu.