Ballymena are top of the Premiership!
Ten-man Newry pulled one back with Dale Montgomery blasting high into the net on 68 minutes.
City keeper Andy Coleman was shown a straight red card after clashing with Cathair Friel nine minutes earlier.
Andy McGrory doubled Ballymena's lead a minute from the break with a crisp shot into the bottom corner.
United went in front after 36 minutes when Adam Lecky tapped in the rebound after a James Knowles shot struck the woodwork.
Newry City: Coleman, Mooney, King, Noonan, Boyle, McCann, Carville, S. Hughes, M. Hughes, Teggart, Montgomery
Subs: Maguire, McCabe, Lavery, Rushe, McArdle, Healy, McCullough
Ballymena United: McDermott, Kane, Addis, Whiteside, Friel, Knowles, McCullough, McGrory, Ervin, Lecky, Re. Glendinning
Subs: McCauley, Burns, Nolan, Shevlin, Balmer, Winchester, McMurray