British light heavyweight Buatsi secured a victory yet unimpressive debut to life under recent management with a decision win over Parker in the Manchester arena.
The Olympic medal winner's punch output seemingly secured him a split decision in a tight ten-round contest at the Manchester venue.
But Parker had his moments, landing some telling single shots in a contest where the approaches never quite clicked, with excessive holding disrupting the contest.
The scoring judges scored it 96-94 for to Buatsi, with the remaining official a even score.
"It wasn't my best display but how do champions respond? They succeed," Buatsi stated in the ringside as he was faced boos from the audience.
The British fighter got back to winning after his first professional defeat - an memorable fight with his previous opponent in February - to secure a twentieth professional win.
Some ringside observers felt the challenger, thirty-one, merited the victory but the contender suffered the second setback of his 28-match professional journey.
Buatsi Earns Victory in Dull Affair
Buatsi's progress has slowed in recent years through management issues and extended periods of inactivity.
Once tipped as the future of the British fight scene, he now is positioned trying to achieve expectations - possibly in what seems like a ultimate opportunity - under recent support.
He began cautiously, with the two boxers prepared to take risks in a cagey initial rounds.
The challenger, whose sole prior loss came at the lower weight class against John Ryder in 2022 after breaking his hand mid-fight, was making just his second bout at the higher weight class.
By the halfway stage, Parker had made it competitive, making life awkward for the favorite, who operated with a solid defense to edge the cleaner rounds.
The audience's tolerance diminished amid frequent holding, with the challenger slipping to the canvas various instances during clinches.
The underdog closed well, but many rounds were hard to judge. Although, former world champion the boxing analyst - commentating on Dazn - had it significantly in favor for Parker, giving Buatsi just a single round.
Buatsi progresses, but with the presence of heavy hitter Benavidez, and Russian star Bivol dominating the weight class, the road to world glory - judging by this showing - still seems difficult.
Hatton Memorial Inspires Manchester Derby Contest
In the supporting bout, Arthur beat Bradley Rea by split-decision in a excellent Manchester vs Manchester contest to win the European light-heavyweight championship.
The venue grew hushed for a profoundly moving homage before the fight as 10 bells rang in memory of Manchester's own Ricky Hatton, who died aged 46 in September.
It was the initial significant broadcast match card in the urban center since Hatton's passing. As the final chime ended, the quiet transitioned to a chant of "there's just one Hatton".
The fighting within the ring reflected the emotion. Arthur was floored by a left hook directly to the chin in the early round, getting up unsteadily to his footing on the referee's count.
But the traditional red equipment of Arthur soon pressed ahead again. Across the ring, Rea - in opposing blue - was marked up soon, heavy swelling developing under his eye as the pair exchanged hard punches.
The challenger, twenty-seven, connected with strong blows but the champion, 34, matched the intensity with effective uppercuts as the intensity rarely dropped over the full distance.
The victor edged the verdict with official scores of draw, 115-113 and 115-112, but the two athletes were determined and brave, all the qualities their hero Hatton embodied.
