The slick orthodox fighter handed Azeez his first professional defeat with a 116-110, 117-109, 117-109 points victory.
Buatsi attacked the body from minute one. The Croydon fighter was elusive, combining jabs and hooks to the frame of Azeez.
The bad blood from the build-up was on full show in round three with the pair swinging in the centre and looking for an early stoppage.
But Buatsi's early body work began to pay off as openings in Azeez's defence allowed him to let his hands go in an explosive fifth round.
Buatsi forced Azeez to fight at his rhythm late on as he began to win consistent rounds.
Azeez was knocked down twice in round 11 which swung a definitive victory in Buatsi's favour.