At Vale Park, Jennison Myrie-Williams put the hosts ahead on the stroke of half-time but they paid the price for not adding more goals and Paul McCallum came off the bench to grab a potentially vital point for the visitors.
Aldershot lie one point from potential safety.
Burton edged into the third and final automatic promotion spot with a 2-0 home win over Wycombe.
Congolese midfielder Jacques Maghoma scored both goals, after 49 and 68 minutes.
Rotherham were emphatic 4-1 winners over Exeter at the New York Stadium.
Ben Pringle got the ball rolling in the first minute for the Millers, with Daniel Nardiello (28), Michael O'Connor (30) and Craig Morgan (51) also notching before Danny Coles' consolation in the 77th minute.
Bradford triumphed by the same scoreline at home to Bristol Rovers.
Nahki Wells scored twice, including a penalty, with Andrew Davies and Garry Thompson also on target for the Bantams, who moved above Exeter into the play-off zone as a result.