Despite the result, it was a solid debut by Day, but Bath were too prolific in front of goal.
A goal from Frankie Artus game the home side the lead going into half-time, with two quick-fire goals in second-half stoppage time, while Hemel were pushing for an equaliser, ultimately sinking The Tudors.
Justin Amaluzor also started the game for Hemel, before getting substituted in the 73rd minute.
Also in action, Joe Payne played 90 minutes as his Solihull Moors side conceded an 80th-minute winner against now top of the National League Dover Athletic.
This now leaves The Moors second from bottom despite a solid performance from the team.