Ballymena are level on points with leaders Crusaders and Portadown at the top of the Premiership table after a pulsating 2-2 draw with Cliftonville.
Matthew Tipton's glancing 36th-minute header put Ballymena in front.
Chris Curran levelled for the Reds after 76 minutes, seconds after United had a penalty appeal turned down.
Jude Winchester drove a piledriver past Dwayne Nelson with two minutes left but substitute Allan Jenkins drilled home a left-foot shot in the final minute.
Striker Joe Gormley was dropped to the bench, with Tiarnan Mulvenna joining David McDaid up front, as Reds manager Tommy Breslin made a number of changes to his starting line-up.
Ballymena's recent good form was reflected in the fact that skipper Jenkins, back after suspension, had to settle for a place among the substitutes.
Glenn Ferguson's side were looking to bring to an end an alarming record of nine straight defeats to the Solitude outfit.
Darren Boyce saw an early effort easily saved by Ryan Brown, while at the other end, Mulvenna was denied by Nelson and Johnny Taylor cleared the danger.
Gary Thompson shot wide and Brown denied Tipton, before the former Portadown and Linfield striker broke the deadlock nine minutes before half-time after meeting Neal Gawley's cross.
Before the break, David McDaid's right-foot free-kick was saved low to his right by Nelson and another free-kick by the same player was deflected over the bar.
After the interval, David Cushley's audacious 40-yard free-kick was well saved by Brown and the visiting keeper then tipped a ferocious goal-bound left-foot effort by the Ballymena winger over the bar.
Brown proved equal to another Cushley attempt, while Tony Kane went close and Martin Donnelly fired straight at Nelson when well placed.
Referee Colin Burns controversially waved away Ballymena penalty appeals for an alleged handball by Ryan Catney, plus a raised flag from his assistant and soon after Chris Curran's slightly deflected shot brought the teams level.
Winchester rattled home what looked to be the winner but Jenkins had the final say with his late leveller to secure a share of the points for the home side after a dramatic match.
Ballymena manager Glenn Ferguson:
"We showed great character to maintain our unbeaten home record, but we are disappointed only to get a point - that shows how far we have come in the last 18 months.
"The officials are meant to work as a team, but that didn't always happen today."