The unbeaten 28-year-old hammered the Bolotniks with a hook in the sixth round then left the Latvian in a crumpled heap after landing a big right in the 11th to signal his 15th straight win.
Stabbing stiff punches, Buatsi took the center of the ring in the first round, but Bolotniks quickly displayed his threat, stiffening South London’s legs with a right hand.
Buatsi responded with crisp body shots in the second, and he responded to another Bolotniks forehand with a clean combination in the third.
More ferocity was added to Buatsi’s work in the fourth quarter as he unleashed a flurry of fire at Bolotniks, who was forced to resist a clean right hand in the fifth.
When a left hook dropped the Bolotniks onto the canvas in the sixth, the fight’s end seemed imminent, but Buatsi appeared to run out with a follow-up assault that failed to move a stubborn opponent.
Buatsi’s punches slipped below the belt line, ultimately resulting in a point deduction in the eighth and the Bolotniks retaliated with provocative punches.
But Buatsi readjusted his accuracy, hitting with his right hand in the dying seconds of the ninth, then exploded with a series of hurtful shots in the 10th.
As the Bolotniks retreated from another stinging assault, Buatsi intervened with a belted right hand that ended the fight in the 11th.
On the undercard, Joe Cordina only needed 53 seconds to inflict a first round knockout on Joshuah Hernandez.
The Welshman knocked down Hernandez with an explosive right hand, forcing the referee to signal the 13th win of Cordina’s undefeated career.