An injury-time equaliser from substitute Andy Morrell won a point for Blackpool at Bloomfield Road.
The Seasiders took the lead in strange fashion when Will Haining's clearance bounced off the feet of former Oldham striker Scott Vernon and into the net.
Oldham midfielder Richie Wellens equalised, before Chris Porter headed home to give Oldham the lead.
Blackpool clinched a point in injury time when Morrell scored his first goal for his new club.
Blackpool: Evans, Barker, Jackson, Evatt, Coid, Gillett (Morrell 70), Southern (Fox 84), Jorgensen, Hoolahan, Burgess, Vernon (Parker 74).
Subs Not Used: Jones, Joseph.
Booked: Southern, Gillett, Evatt, Morrell.
Goals: Vernon 41, Morrell 90.
Oldham: Pogliacomi, Eardley (Rocastle 66), Haining, Stam, Charlton, Liddell, Wellens, McDonald, Taylor (Wood 88), Warne (Grabban 79), Porter.
Subs Not Used: Ryan Smith, Trotman.
Booked: Wellens, Porter.
Goals: Wellens 63, Porter 72.
Ref: M Jones (Cheshire).