The visitors scored in the eighth minute of stoppage time to nick a point, despite having had James Petronzio sent off midway through the first-half, his handball stopping a goalbound shot on the line and Alfie Dodsworth netting the resultant penalty.
Fraser Paprill levelled the scores on 67 minutes but Adam Scott soon restored Ollerton’s lead.
Kevan Kahoussi quickly levelled again on 75 before another spot kick went the hosts’ way, again Dodsworth netting from 12 yards.
But Batty struck in the dying seconds to level the scores and earn a share of the points.
Brigg go to Garforth in the League Cup on Wednesday (4th) before hosting second-placed Rossington Main in the league on Saturday.