Hutchinson, 28, was first to step on to the scales at Friday’s ceremonial weigh-in and was greeted by huge cheers from his boisterous following.
Buatsi, however, had to be weighed twice in the official weigh-in on Friday morning after he was initially an ounce (28 grammes) over the light-heavyweight limit.
The 33-year-old made the championship weight of 12st 7lb (79kg) at the second attempt after taking his clothes off, with Hutchinson then making a derogatory reference to Buatsi being overweight when they came face to face later in the evening.
Buatsi, who won Olympic bronze in 2016, goes into the biggest fight of his career with a record of 20 wins and one defeat as a professional.
Hutchinson, the first Scottish boxer to win gold at an amateur World Championships, also has a record of 20 wins and two defeats.