UK light-heavyweight Buatsi secured a victory yet underwhelming start to his career under fresh promotional backing with a unanimous decision over Zach Parker in Manchester.
The Olympic bronze medallist's activity level seemingly secured him a majority decision in a close 10-round contest at the Manchester venue.
But the challenger had his moments, landing some telling individual punches in a contest where the techniques didn't complement each other, with constant grabbing marring the action.
Two judges had it 96-94 for to the winner, with the final judge a even score.
"It wasn't my finest display but how do champions respond? They prevail," Buatsi commented in the ringside as he was met by negative reactions from the crowd.
The British fighter returned to winning ways after his first professional defeat - an thrilling contest with Callum Smith in February - to secure a 20th career victory.
Several boxing experts felt Parker, thirty-one, should have been awarded the win but the Derbyshire fighter suffered the second loss of his 28-bout professional journey.
The Champion Claims Win in Uneventful Match
The fighter's advancement has stalled in recent times through promotional disputes and considerable time of inactivity.
Previously predicted as the next star of British boxing, he now stands trying to realize his potential - perhaps in what appears to be a final roll of the dice - under fresh management.
He began cautiously, with both competitors willing to take risks in a tentative opening few rounds.
The challenger, whose sole prior loss came at super middleweight against his former opponent in two years ago after breaking his hand during the bout, was participating in his second bout at light heavyweight.
By the middle rounds, Parker had stayed in contention, causing problems for Buatsi, who worked behind a solid defense to barely take the more effective rounds.
The spectators' acceptance diminished amid constant clinching, with the challenger falling to the floor several times during clinches.
The underdog closed well, but many rounds were hard to judge. Nevertheless, ex-champion the boxing analyst - providing analysis for Dazn - had it particularly wide for the challenger, scoring for Buatsi just only one stanza.
Buatsi progresses, but with the caliber of power puncher Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the road to world glory - judging by this showing - still seems difficult.
Hatton Tribute Fuels Local Rivalry Contest
In the co-main event, Arthur overcame Bradley Rea by divided decision in a outstanding local rivalry fight to capture the European light-heavyweight title.
The stadium grew hushed for a deeply poignant tribute ahead of the contest as a bell ceremony sounded in honor of the city's native Hatton, who died 46 years old in recently.
It was the first major televised match card in the location since the passing of Hatton. As the concluding sound ended, the stillness became a shout of "there's just one Ricky Hatton".
The action inside the ropes equaled the emotion. The eventual winner was sent to the canvas by a powerful punch squarely on the jaw in the second round, getting up unsteadily to his feet on the count of eight.
But the Manchester United-red equipment of Arthur soon pressed ahead again. Across the ring, Rea - in rival City blue - was marked up soon, heavy swelling developing under his orbital area as the fighters traded powerful shots.
Rea, twenty-seven, landed power punches but the champion, thirty-four, fought fire with fire with effective uppercuts as the intensity hardly diminished over 12 rounds.
Arthur edged the result with judges scorecards of 114-114, 115-113 and clearer margin, but each competitor were persistent and brave, everything their idol Hatton represented.
