UK light heavyweight Buatsi secured a victory yet unimpressive start to his career under recent management with a points victory over Zach Parker in Manchester.
The Olympic medal winner's work rate appeared to earn him a judges' verdict in a close 10-round bout at the Manchester venue.
But the challenger found success, landing some telling individual punches in a fight where the approaches never quite clicked, with excessive holding disrupting the fight.
The officials scored it 96-94 to Buatsi, with the remaining official a 95-95 draw.
"It wasn't my best display but what defines champions? They prevail," Buatsi said in the ringside as he was greeted with disapproval from the crowd.
The British fighter got back to winning after his first professional defeat - an thrilling contest with Callum Smith in February - to secure a 20th career victory.
Some ringside observers thought the challenger, thirty-one, deserved the win but the contender experienced the second loss of his 28-match career.
Buatsi Earns Win in Uneventful Encounter
His career development has slowed in recent times through management issues and considerable time of inactivity.
Earlier forecast as the future of UK boxing, he now is positioned trying to realize his potential - maybe in what feels like a ultimate opportunity - under new promotional backing.
He began cautiously, with neither fighter willing to overcommit in a tentative initial rounds.
Parker, whose single earlier setback came at super-middleweight against his former opponent in two years ago after damaging his hand during the bout, was participating in his second bout at light-heavyweight.
By the fight's midpoint, Parker had stayed in contention, making life awkward for the favorite, who utilized a tight guard to edge the better rounds.
The audience's tolerance decreased during constant clinching, with Parker slipping to the canvas several times during grappling.
The underdog closed well, but multiple periods were challenging to assess. Nevertheless, ex-champion Carl Frampton - providing analysis for the broadcast network - had it significantly in favor for the challenger, awarding Buatsi just one round.
Buatsi moves on, but with the likes of hard hitter Benavidez, and Russian star Dmitry Bivol dominating the weight class, the path to championship success - based on this performance - still appears challenging.
Hatton Memorial Fuels Manchester Derby Contest
In the secondary fight, Arthur overcame Rea by close verdict in a outstanding Manchester vs Manchester battle to secure the European light heavyweight championship.
The stadium fell silent for a extremely emotional homage prior to the bout as 10 bells tolled in remembrance of local hero Ricky Hatton, who passed away aged 46 in last month.
It was the premier televised match card in the location since Hatton's death. As the last bell ended, the quiet transitioned to a shout of "there's just one Ricky Hatton".
The fighting during the bout reflected the feeling. Arthur was sent to the canvas by a powerful punch directly to the jaw in the early round, standing uncertainly to his position on the eight count.
But the Manchester United-red shorts of Arthur soon came forward again. Across the ring, the opponent - in opposing blue - was marked up quickly, heavy swelling appearing under his orbital area as the pair traded punishing blows.
Rea, twenty-seven, connected with strong blows but the champion, 34, matched the intensity with effective uppercuts as the pace seldom decreased over 12 rounds.
The victor narrowly won the result with judges scorecards of draw, 115-113 and wider gap, but each competitor were determined and courageous, exactly what their idol Hatton embodied.
