Nathan McConnell equalised nine minutes into added time against nine-man United in a dramatic Showgrounds encounter.
Paul Kirk and Tommy Wright confront each other
Simon Kelly scored the opener from close range on 46 but was then sent-off for handling a Chris Kingsberry cross, Darren Armour scoring the penalty.
Albert Watson headed Ballymena ahead but Craig McClean was then sent-off for a bad tackle on Peter McCann.
Paul Murphy was taken off with a leg injury, Kevin Kelbie went into goal and McConnell fired in a low shot for 2-2.
There were ugly scenes after the final whistle with reports of missiles being thrown.