The final scorecards were 113-111, 115-110, 114-111, all in favour of Whyte.
Whyte managed to knock Parker down twice in the fight with Parker then scoring a dramatic late knockdown on Whyte in the final round that nearly knocked him out.
Shiloh Jasmine Parker was born when I was in camp preparing for this fight against Dillian Whyte so going back to New Zealand and meeting her for the first time will be special. I put on a good show last time out at The O2 and I'll be looking to do the same tonight.
But Whyte held on for a deserved win over New Zealander Parker (24-2, 18 KOs), his eighth since his only professional defeat to Joshua who he beat as an amateur.
Anthony Joshua The IBF, WBA and WBO champion, 28, next fights Russia's Alexander Povetkin at Wembley Stadium on September 22.
The other heavyweight bout features the always unpredictable Dereck Chisora against Carlos Takam.
Whyte headlined his first PPV in the United Kingdom (outside of Joshua) in his own right against the former world champion in Parker, who was coming into the encounter following his world heavyweight unification fight with Anthony Joshua in March.
A world title challenge against Anthony Joshua could now be on the cards for Whyte.
"I would like to fight Joshua again", he said. Whyte would be buzzed and rocked by Parker from the onslaught of hard shots nearly snatching victory from the jaws of defeat. Dillian is on the cusp of fighting for a World title and beating him would put me right back at that top table. Despite being stopped, Whyte had his moments, and was even able to hurt Joshua.
Parker, 26, from South Auckland who trains in Las Vegas, caused Whyte problems in the first round with his hand speed and an effective jab.
Building up a lead with his aggression, Whyte unexpectedly knocked down Parker in the ninth round with a left counter.
There seemed to be nearly confusion by Parker at the rough-house tactics he surely knew Whyte, with a kickboxing and MMA background, would employ.
Whyte wilted in the final round, a straight right sending him down, but found the strength to rise again and make it through to the end, allowing him to record a unanimous triumph on the scorecards. Whyte began to tire, and it looked like Parker could power his way home as he began to land some punches on his British opponent.
"I fought someone who is very experienced", Whyte said.
As for Parker, it is time to go back to the drawing board.