A Chris Porter brace and an own goal saw in-form Gillingham blown away by rampant Oldham on Saturday.
Oldham's Will Haining struck after four minutes with a close-range volley and Porter soon doubled the lead.
Just after the break, Latics defender Simon Charlton lobbed Scott Flinders from 10 yards inside his own half.
The Gills pulled one back five minutes later with a Mike Flynn penalty after Neal Eardley's foul on Gary Mulligan and Porter scored his second late on.
Oldham: Pogliacomi, Eardley, Haining, Stam, Charlton (Rocastle 58), Warne (Grabban 83), Wellens, McDonald, Taylor, Porter, Liddell.
Subs Not Used: Ryan Smith, Hall, Trotman.
Goals: Haining 4, Porter 24, Charlton 46, Porter 90.
Gillingham: Flinders, Jupp, Cox, Johnson, Jackman, Bentley, Flynn, Crofts (Spiller 45), Easton (Ndumbu-Nsungu 45), Mulligan, Jarvis.
Subs Not Used: Pouton, McDonald, Clohessy.
Goals: Flynn 51 pen.
Ref: T M Kettle (Rutland).