Smolka continued his barrage, controlling almost four minutes of the five-minute round. Taking Nguyen to ground twice, the Hawaiian landed a total of 79 shots, and was challenged by just one leg kick in return.
Such an onslaught would usually call for the referee to intervene and end the fight, however despite a number of clear opportunities, Dean allowed the flurry of punches to continue.
The ground and pound reached its savage peak with just 19 seconds remaining in the round, when Dean finally called for a TKO. At the same time, Nguyen's corner tried to end the fight, throwing in a towel to try limit the damage.
By the time the fight was eventually called, Smolka had landed a total of 138 strikes, 92 per cent of which were directed at the head of his opponent. In comparison, Nguyen had landed just eight.
Fans on social media slammed Dean for not ending the fight sooner. Even UFC President Dana White was relieved when the fight was over.
While there is no doubt the fight should have been stopped a lot sooner than it was, none could deny Nguyen's courage in attempting to defend himself and keep the fight going as long as possible.
Late last month, a Legacy FC referee came under fire for failing to call off a fight, which nearly saw one fighter choke another to within an inch of his life.
Former Legacy Fighting Championship bantamweight title holder Manny Vazquez was defending his title against Steven Pearson in Dallas, Texas on June 26.
As the bout approached the fourth round, both fighters had dished out their fair share of solid shots, making the judge's job incredibly difficult should it go the distance.
Fortunately for the judges, the bout ended in the fourth round. Not so fortunate, however, was how Pearson ended it - and it nearly cost Vazquez more than just the fight.
As the pair wrestled on the canvas, Pearson was able to lock in a rear-naked choke hold on his opponent, putting him to sleep almost immediately.
However despite Vazquez's clear lack of consciousness, the Legacy FC referee failed to step in immediately and stop the fight.
The 22-year-old unconscious fighter could be seen convulsing while still locked in the choke hold.
Popular video editor page Zombie Prophet posted the footage on Twitter, claiming that the ref "almost kills a fighter".
The incident sparked outrage among fans, who left frustrated comments on the video.
"Seriously, if that guy refs another fight the commission should be disbanded," one user said.
"That's not 'on the fighter'...The ref has one job," said another.
"I'm pretty sure he goes limp 3 seconds into this (video). At the very least the ref should have checked his arm then. This is scary," another user wrote.
