UK light-heavyweight Buatsi earned a win yet disappointing debut to his career under recent management with a unanimous decision over Zach Parker in Manchester.
The Olympic bronze medallist's punch output seemingly secured him a judges' verdict in a competitive ten-round contest at the Co-op Live Arena.
But the challenger landed significant shots, connecting with powerful clean blows in a fight where the techniques failed to mesh, with frequent clinching disrupting the fight.
The officials judged it 96-94 in favor to the winner, with the third a 95-95 draw.
"It wasn't my greatest display but how do champions respond? They prevail," the victor stated in the ring as he was met by negative reactions from the crowd.
The British fighter got back to winning after his maiden career setback - an memorable fight with his previous opponent in last winter - to earn a twentieth professional win.
Various analysts felt Parker, thirty-one, deserved the win but the contender suffered the second loss of his 28-bout career.
The Champion Secures Win in Dull Match
Buatsi's progress has slowed in recent times through management issues and considerable time of inactivity.
Previously predicted as the next star of the British fight scene, he now stands trying to realize his potential - perhaps in what feels like a final roll of the dice - under fresh management.
He opened tentatively, with the two boxers prepared to be aggressive in a cagey opening few rounds.
Parker, whose single earlier setback came at super-middleweight against John Ryder in two years ago after damaging his hand mid-fight, was participating in his second fight at the higher weight class.
By the fight's midpoint, Parker had kept it close, making life awkward for Buatsi, who operated with a tight guard to edge the more effective rounds.
The audience's tolerance diminished because of regular grabbing, with the challenger slipping to the canvas several times during grappling.
Parker ended stronger, but many rounds were difficult to score. However, previous titleholder the boxing analyst - working with Dazn - had it particularly wide for the challenger, scoring for Buatsi just only one stanza.
The victor advances, but with the presence of hard hitter Benavidez, and Russian champion Dmitry Bivol leading the category, the journey to titles - on this evidence - still seems difficult.
Hatton Homage Inspires Manchester Derby Fight
In the supporting bout, Arthur defeated Bradley Rea by divided decision in a terrific Manchester vs Manchester contest to secure the continental championship.
The stadium grew hushed for a profoundly moving homage prior to the bout as ten bells tolled in honor of local hero Ricky Hatton, who died at age 46 in recently.
It was the first major televised boxing event in the urban center since Hatton's death. As the concluding sound ended, the stillness gave way to a chant of "there's just one Hatton".
The fighting during the bout equaled the feeling. The eventual winner was knocked down by a powerful punch directly to the chin in the initial stage, rising shakily to his position on the count of eight.
But the red-colored attire of the fighter soon came forward again. Across the ring, the opponent - in competitive blue - was damaged early, heavy swelling developing under his orbital area as the duo traded punishing blows.
Rea, twenty-seven, landed power punches but the champion, 34, responded in kind with stinging uppercuts as the intensity hardly diminished over 12 rounds.
The victor barely secured the verdict with scoring tallies of draw, narrow lead and wider gap, but the two athletes were persistent and courageous, exactly what their inspiration the legend embodied.
