Whyte earned a unanimous decision in the bout which saw both boxers knocked down in an enthralling encounter.
Parker was floored following a clash of heads in the second round before Whyte knocked him down in the ninth.
The Brit looked to be dominating before a late fightback from the New Zealander saw Whyte hit the canvas in the final round.
It made no difference to the result with all three judges giving the bout to Whyte.
In knocking Parker down, 30-year-old Whyte became the first person to put the former WBO heavyweight world champion on the deck.
Even Anthony Joshua didn’t manage that when he went the distance with Parker back in March.
And though Whyte’s clash with 26-year-old Parker saw the Brixton man show his power, Bellew was still not overly impressed with his performance.
“If you were a boxer, how would you want to beat Joseph Parker? The way Dillian Whyte did or the way Anthony Joshua did?” Bellew asked iFL TV.
“I’m a boxer. I don’t want to go in the ring and get dropped. Anthony thoroughly outboxed Parker and owned him on the night.
“Dillian Whyte owned Parker for ten rounds and then gassed. But ultimately he showed what heart, determination and commitment can get you in boxing.
“Dillian Whyte technically isn’t very good. He’s got balance issues, he’s all over the place at times but he’s got a heart of steel.”
Whyte’s victory could set up a rematch with Joshua with the pair having clashed in December 2015.
Joshua stopped Whyte in the seventh round on that occasion, though both fighters have drastically improved.
Joshua next steps into the ring when he faces Alexander Povetkin at Wembley on September 22.