British light heavyweight Buatsi secured a victory yet underwhelming start to life under fresh promotional backing with a decision win over Zach Parker in Manchester.
The Olympic bronze medallist's work rate appeared to earn him a majority decision in a tight ten-round contest at the Co-op Live Arena.
But Parker found success, landing some telling individual punches in a contest where the techniques never quite clicked, with frequent clinching spoiling the action.
The scoring judges scored it 96-94 to the winner, with the third a 95-95 draw.
"It wasn't my greatest display but how do champions respond? They succeed," the victor commented in the ringside as he was met by negative reactions from the spectators.
The British fighter bounced back after his initial pro loss - an memorable fight with his previous opponent in last winter - to claim a 20th pro success.
Several boxing experts believed Parker, thirty-one, merited the win but the Derbyshire fighter experienced the second loss of his 28-fight career.
The Champion Secures Triumph in Dull Encounter
His career development has slowed in recent years through promotional disputes and considerable time of inactivity.
Once tipped as the next star of the British fight scene, he now stands trying to achieve expectations - maybe in what seems like a last chance - under fresh management.
He began cautiously, with the two boxers willing to take risks in a tentative early stages.
The challenger, whose single earlier setback came at super middleweight against his former opponent in two years ago after breaking his hand in the contest, was making just his second fight at light heavyweight.
By the middle rounds, Parker had made it competitive, making life awkward for the favorite, who worked behind a protective stance to narrowly win the cleaner rounds.
The crowd's patience wore thin during frequent holding, with the challenger falling to the floor several times during clinches.
Parker finished the stronger, but multiple periods were challenging to assess. Although, previous titleholder Carl Frampton - providing analysis for the broadcast network - had it significantly in favor for the challenger, giving Buatsi just a single round.
The victor advances, but with the caliber of heavy hitter Benavidez, and Russian star Bivol ruling the division, the path to championship success - judging by this showing - still appears challenging.
Hatton Homage Motivates All-Manchester Battle
In the secondary fight, Arthur beat Bradley Rea by divided decision in a terrific local rivalry fight to capture the European light-heavyweight title.
The arena became quiet for a deeply poignant homage prior to the bout as ten bells tolled in memory of Manchester's own Ricky Hatton, who died 46 years old in September.
It was the initial significant broadcast boxing event in the location since Hatton's passing. As the concluding sound faded, the silence gave way to a chant of "only one Hatton".
The action within the ring equaled the emotion. The eventual winner was sent to the canvas by a left hook squarely on the face in the second round, getting up unsteadily to his position on the count of eight.
But the Manchester United-red attire of the fighter soon pressed ahead again. Across the ring, Rea - in opposing blue - was injured quickly, heavy swelling appearing under his orbital area as the duo exchanged powerful shots.
Rea, twenty-seven, landed power punches but Arthur, thirty-four, responded in kind with powerful upward punches as the intensity rarely dropped over the full distance.
Arthur narrowly won the verdict with judges scorecards of 114-114, close margin and clearer margin, but the two athletes were relentless and full of heart, everything their hero the legend embodied.
