Wilder recorded the 40th knockout of his career just two minutes, 17 seconds into the fight at Barclays Center in New York.
Wilder (41-0-1) started well and capitalised, landing the decisive blow quickly against his rival and fellow American.
After a war of words in the build-up, Wilder showed his class in his first fight since drawing with Tyson Fury in December, his performance set to again lead to calls for a rematch with the Brit or fight with fellow heavyweight champion Anthony Joshua.