Joseph Parker overcame the shock of suffering a knockdown inside the opening seconds to record a split-decision points win over a disgruntled Dereck Chisora in Manchester.

A clash between two heavyweights with aspirations of challenging for a world title in the not-too-distant future went the distance despite an eventful start to proceedings.

The first punch by either boxer saw Chisora land a looping right hand that caught his rival cold, dropping him to the canvas.

However, Parker recovered quickly enough to not only beat the count from the referee but also quell Chisora's ensuing attempts to force a stunning stoppage.

The New Zealander – who previously held the WBO belt – was second best in the early going but warmed to his task as the rounds ticked by, aided by a probing jab that set up opportunities to attack.

His work in the second half of the bout was enough to impress two of the judges at ringside, Parker getting the nod by scores of 115-113 and 116-111.

Yet Chisora's strong opening saw the other official on duty give it to him by a 115-113 margin. He made clear his disappointment in the verdict in his post-fight interview, too.

"I can't get upset. It's horrible. I give everything. These are the results I get," 'Del Boy' told Sky Sports Box Office. "If he wants to give me the rematch, I will take it."

W @joeboxerparker #ChisoraParker pic.twitter.com/FBETKBj4Cc
— Matchroom Boxing (@MatchroomBoxing) May 1, 2021

Parker seemed ready to do just that in the immediate aftermath, having accepted it was a close call in the final reckoning.

"We can do a rematch in the next fight," he said after improving his record to 29-2, though this was his first victory since switching to work with new trainer Andy Lee.

"It was a tough fight. I got caught at the beginning so I dug deep and stayed focused. It was close. It could have gone either way."

The fight had appeared in serious doubt on Friday due to a coin toss after the weigh-in deciding the order in which they would walk to the ring before the bout.

Chisora made clear he was ready to go home unless he came out second, though his promoter David Haye revealed how the intervention of the British fighter's mother, Viola, made sure her son stayed put.

On the undercard, Katie Taylor retained her WBA, WBC, IBF and WBO lightweight belts with a points win over Natasha Jonas.

The duo did not disappoint in a rematch of their fight at the London 2012 Olympic Games, Taylor edging it 96-94 and 96-95 twice on the scorecards, in the process remaining unbeaten as a professional.