British light heavyweight Buatsi made a winning yet unimpressive start to his career under recent management with a decision win over Zach Parker in Manchester.
The Olympic medal winner's activity level likely gained him a judges' verdict in a tight ten-round contest at the Co-op Live Arena.
But Parker landed significant shots, connecting with powerful individual punches in a match where the approaches failed to mesh, with frequent clinching marring the contest.
The officials had it 96-94 to Buatsi, with the final judge a 95-95.
"It wasn't my greatest showing but what do champions do? They win," Buatsi said in the ring as he was greeted with disapproval from the spectators.
The Londoner bounced back after his first professional defeat - an epic battle with Callum Smith in last winter - to secure a twentieth professional win.
Several boxing experts thought Parker, thirty-one, merited the decision but the contender endured the second loss of his 28-match professional journey.
Buatsi Earns Triumph in Slow Match
His career development has plateaued in recent times through promotional disputes and long spells of lack of fights.
Once tipped as the future of British boxing, he now is positioned trying to realize his potential - maybe in what feels like a ultimate opportunity - under fresh management.
He started carefully, with neither fighter willing to overcommit in a tentative initial rounds.
Parker, whose only previous defeat came at super-middleweight against John Ryder in two years ago after damaging his hand in the contest, was participating in his second fight at the higher weight class.
By the halfway stage, Parker had kept it close, creating difficulties for the favorite, who operated with a solid defense to narrowly win the cleaner periods.
The audience's tolerance wore thin amid frequent holding, with the challenger falling to the floor various instances during grappling.
The underdog closed well, but several stanzas were hard to judge. However, ex-champion Carl Frampton - commentating on the broadcast network - had it significantly in favor for Parker, awarding Buatsi just only one stanza.
Buatsi advances, but with the caliber of hard hitter Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the journey to titles - judging by this showing - still seems difficult.
Ricky Hatton Memorial Inspires All-Manchester Fight
In the co-main event, Arthur overcame Rea by split-decision in a outstanding Manchester vs Manchester fight to capture the European light heavyweight title.
The venue grew hushed for a profoundly moving homage prior to the bout as 10 bells sounded in honor of the city's native Ricky Hatton, who passed away at age 46 in recently.
It was the premier televised fight night in the urban center since Hatton's death. As the last bell disappeared, the quiet transitioned to a roar of "there's just one Hatton".
The competition inside the ropes matched the sentiment. Arthur was knocked down by a powerful punch flush on the jaw in the second round, standing uncertainly to his position on the eight count.
But the red-colored attire of the fighter soon came forward again. From the other corner, the opponent - in opposing blue - was damaged quickly, noticeable damage forming under his eye as the fighters landed hard punches.
Rea, 27, connected with strong blows but Arthur, 34, fought fire with fire with effective uppercuts as the action rarely dropped over twelve rounds.
The victor narrowly won the decision with scoring tallies of even score, close margin and 115-112, but both fighters were relentless and courageous, everything their idol Hatton represented.
