The 30-year-old Briton secured his eighth win in a row as he overpowered the former WBO heavyweight champion in Saturday's showpiece.
Parker started brightly, causing Whyte problems in the first round with his hand speed and an effective jab, and went on to land a big right in the second.
Although Parker was given a count - the first of his professional career - after getting in a tangle with Whyte, the New Zealander was back in his rhythm in the third and continued to have the edge over his opponent.
However, Whyte grew more into the encounter from the sixth round onwards, landing a big right uppercut before unloading successful combinations.
Parker became ever more fatigued as the bout went on and was caught out by a ferocious left hook to the jaw in the ninth round which sent him to the canvas again.
Whyte was very much in control of the fight at this stage but Parker went for broke in the final two rounds, even succeeding in knocking his opponent in the last minute with a right to the top of the head.
However, Whyte was able to get up as the final bell rang, and the judges gave the fight unanimously to Londoner by scores of 113-111 115-110 114-111 to bolster his claims for a world title fight.