British light-heavyweight Buatsi earned a win yet underwhelming beginning to his career under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic medal winner's work rate likely gained him a split decision in a competitive ten-round fight at the Co-op Live Arena.
But the challenger found success, landing some telling individual punches in a fight where the styles failed to mesh, with constant grabbing spoiling the action.
The scoring judges had it 96-94 to the winner, with the third a even score.
"It wasn't my greatest showing but what do champions do? They win," Buatsi said in the ring as he was faced disapproval from the crowd.
The Londoner bounced back after his maiden career setback - an epic battle with his previous opponent in last winter - to secure a 20th pro success.
Some ringside observers believed the challenger, thirty-one, merited the win but the contender experienced the second setback of his 28-match professional journey.
Buatsi Earns Triumph in Slow Encounter
The fighter's advancement has stalled in the past few years through contract problems and long spells of inactivity.
Previously predicted as the next star of the British fight scene, he now stands trying to realize his potential - possibly in what seems like a final roll of the dice - under recent support.
He opened tentatively, with both competitors ready to be aggressive in a calculated initial rounds.
Parker, whose only previous defeat came at the lower weight class against John Ryder in two years ago after breaking his hand mid-fight, was competing in only his second fight at light heavyweight.
By the fight's midpoint, Parker had kept it close, making life awkward for Buatsi, who worked behind a solid defense to barely take the more effective periods.
The spectators' acceptance wore thin during regular grabbing, with Parker falling to the floor various instances during clinches.
Parker closed well, but several stanzas were hard to judge. Although, former world champion Carl Frampton - providing analysis for the broadcast network - had it particularly wide for the challenger, awarding Buatsi just only one stanza.
Buatsi moves on, but with the likes of heavy hitter Benavidez, and Eastern European fighter Bivol leading the category, the path to championship success - based on this performance - still looks steep.
Ricky Hatton Homage Motivates Manchester Derby Battle
In the supporting bout, Arthur overcame Rea by split-decision in a excellent local rivalry fight to secure the European light-heavyweight title.
The venue grew hushed for a profoundly moving memorial prior to the bout as 10 bells sounded in honor of the city's native Ricky Hatton, who succumbed 46 years old in recently.
It was the initial significant broadcast fight night in the urban center since Hatton's death. As the last bell disappeared, the stillness transitioned to a roar of "only one Hatton".
The fighting during the bout equaled the emotion. Arthur was sent to the canvas by a significant blow flush on the chin in the second round, getting up unsteadily to his feet on the count of eight.
But the Manchester United-red shorts of Arthur soon came forward again. From the other corner, Rea - in opposing blue - was damaged early, heavy swelling forming under his face as the pair exchanged powerful shots.
The challenger, 27, landed power punches but the champion, 34, matched the intensity with powerful upward punches as the pace rarely dropped over 12 rounds.
Arthur barely secured the decision with official scores of draw, 115-113 and 115-112, but each competitor were determined and brave, everything their inspiration Hatton represented.
