British light heavyweight Buatsi secured a victory yet disappointing beginning to his career under recent management with a decision win over Zach Parker in the Manchester arena.
The Olympic bronze medallist's punch output appeared to earn him a split decision in a close ten-round fight at the Co-op Live Arena.
But Parker had his moments, delivering effective single shots in a match where the techniques didn't complement each other, with constant grabbing spoiling the contest.
Two judges scored it 96-94 to Buatsi, with the third a even score.
"It wasn't my best display but how do champions respond? They win," Buatsi said in the ring as he was greeted with disapproval from the spectators.
The British fighter got back to winning after his first professional defeat - an thrilling contest with his previous opponent in last winter - to earn a 20th career victory.
Various analysts felt Parker, 31, deserved the win but the contender experienced the second loss of his 28-match professional journey.
The Champion Claims Victory in Uneventful Encounter
Buatsi's progress has plateaued in the past few years through contract problems and extended periods of inactivity.
Once tipped as the future of British boxing, he now stands trying to achieve expectations - perhaps in what feels like a final roll of the dice - under fresh management.
He began cautiously, with neither fighter prepared to take risks in a tentative initial rounds.
Parker, whose single earlier setback came at the lower weight class against his former opponent in two years ago after suffering a hand injury in the contest, was participating in his second appearance at light-heavyweight.
By the middle rounds, Parker had kept it close, making life awkward for Buatsi, who worked behind a solid defense to barely take the more effective rounds.
The crowd's patience decreased during regular grabbing, with Parker slipping to the canvas several times during close exchanges.
The underdog finished the stronger, but multiple periods were challenging to assess. Although, former world champion Carl Frampton - working with Dazn - had it particularly wide for the challenger, scoring for Buatsi just only one stanza.
The victor moves on, but with the caliber of heavy hitter Benavidez, and Russian star Dmitry Bivol leading the category, the path to championship success - judging by this showing - still seems difficult.
Ricky Hatton Memorial Inspires All-Manchester Contest
In the co-main event, Lyndon Arthur overcame Rea by split-decision in a outstanding local rivalry contest to capture the European light-heavyweight title.
The arena fell silent for a profoundly moving tribute before the fight as 10 bells sounded in memory of Manchester's own Hatton, who passed away aged 46 in last month.
It was the first major televised boxing event in the city since Hatton's death. As the final chime disappeared, the stillness became a shout of "there's only one Hatton".
The action within the ring equaled the emotion. The eventual winner was floored by a significant blow flush on the jaw in the initial stage, getting up unsteadily to his position on the count of eight.
But the red-colored equipment of the fighter soon advanced again. Across the ring, Rea - in opposing blue - was damaged quickly, significant bruising appearing under his eye as the fighters exchanged punishing blows.
The challenger, 27, landed power punches but Arthur, thirty-four, matched the intensity with stinging uppercuts as the action seldom decreased over twelve rounds.
The victor barely secured the result with official scores of 114-114, close margin and 115-112, but each competitor were persistent and full of heart, everything their inspiration Hatton stood for.
