With the loss, Chapel Hill (7-3) dropped one game behind first-place Nichirin (8-2), but in reality two games back, because Nichirin has defeated the Farm Center in both of their meetings this season.
Chapel Hill scored three times in both the first and second innings.
After starting pitcher Tanner Garvin held Nichirin scoreless in the home half of the first, Leonard drove in three more runs in the second with a bases-loaded double.
A-Plus began to chip away at the lead, scoring two runs in the home half of the inning on a sacrifice fly by Ethan Evans and an RBI fielder's choice by Bryce Wunderlin.
After a scoreless third inning by both squads, Wunderlin knocked in another run with an RBI single to right field, cutting the Farm Center's lead in half at 6-3.
In the top of the fifth, Chapel Hill loaded the bases on walks to Jake Simpson, a single by Clay Watson and another base on balls to Jesse Darnell.
Boone Sweeney walked to send Simpson to the plate, but Sullivan, who came on in relief of starter Dunn Crowder to begin the frame, induced a ground ball to third to end the threat and limit the damage.
Garvin drilled a ground rule double to begin the sixth and Jesse Pruitt followed with a walk, but once again Sullivan got out of the inning on a pop-up to second, a ground ball back to the mound and an inning ending whiff.
Pruitt, who relieved Garvin in the fifth, got the first two batters out in the sixth before A-Plus began the comeback on a Sullivan single to center.
Brooks Leftwich was beaned by Pruitt to put runners on first and second and a balk sent both runners up one base, but not for long as Evans drilled a two-run single to right field, making it a 7-5 ballgame.
Pruitt hit Wunderlin with a pitch and bloodied his nose.
Crowder replaced Wunderlin at first and Triston Underwood came to the batter's box and bashed a clutch single to right field, sending Evans home and Crowder followed him in with the tying run on a throwing error.
Zach Smith followed with a grounder to third that was misplayed and Underwood pranced in with the go-ahead run.
Sullivan slammed the door shut when he retired the side in order in the bottom of the inning to complete the comeback for the collision boys.
Sullivan picked up the win on the mound and went 1-2 at the plate with a base on balls and two runs scored.
Evans had a huge night, going 2-2 with three RBIs and two runs scored, Leftwich was beaned twice, walked once, had one hit in two at bats and scored three of A-Plus's runs in the game.
Wunderlin, who returned to the game after being hit drove home two runs and had one hit and Underwood managed one hit in in three at bats and scored one run.
Leonard continued his march to the RBI title with four more ribbies and Oliver, Sweeney, Pruitt, Garvin, and Watson all had one base knock apiece for Chapel Hill, who could not take full advantage of 10 walks issued by A-Plus.
Darnell walked four times in five at bats and scored two runs.