Playing in their first league game at The Oval since August Bank Holiday Monday, United welcomed back Wes Tate to the starting XI.
Tate had been absent for the past three fixtures whilst playing for Peacehaven & Telscombe, but his return boosted the options of Simon Rowland.
Haywards Heath had enjoyed a good start to the season on their return to senior football having lost just once in a league match since September 2012 and Andy Tuckey came close to giving Heath the lead with a 25 yard effort that rebounded off the crossbar.
Matt Maclean was denied his first goal in a United shot by a last gasp block on the goaline.
Maclean soon turned provider for Ryan McBride, but the big frontman could only place his header wide of the goal.
Maclean and McBride combined again in the 36th minute but this time McBride did score. Maclean caught a Heath defender in possession after a short goal kick and played in McBride confidently slotted the ball home.
An instinctive double save by Heath 'keeper George Hyde kept United's lead a single goal as he denied McBride before reacting quickly to thwart Maclean.
Heath were forced into changing 'keeper at half-time as Hyde sustained an injury to his hand during the first half.
Tate looked comfortable in midfield on his return and played a delightful cross-field pass to Jason Taylor who tried to play in McBride and Maclean but his centre was just too high for the pair.
United extended their lead on 63 minutes when Tate released McBride on the left wing, who proceeded to pick out the run of Taylor who placed the ball in the bottom corner.
Heath didn't let United have it all their own way however as Mike Williamson forced Grant Young into a smart save with his feet.
United made a double substitution on 74 minutes with Ashley Darby brought on for his home debut and Casey Ham entering the fray.
Less than a minute after his introduction, Ham was on the scoresheet. Indecision in the Heath defence saw the ball fall to him on the edge of the area and he rifled home his effort.
Ham turned provider for United's fourth goal as he produced an inch perfect knock for Linton Rogers who looped a header over replacement 'keeper Graham Leach as United recorded an impressive victory over one of the early season pacesetters in SCFL Division Two.