Oldham scored three times in seven second-half minutes to dump Nottingham Forest out of the FA Cup this afternoon.
Forest took the lead early on when Simon Cox tucked home a cross from Andy Reid, with the final touch coming from Oldham defender Matt Smith.
Paul Dickov's side responded well after the break and equalised when Robbie Simpson lashed home from distance.
Simpson was at it again three minutes later to give Oldham the lead, guiding home a composed header to stun the home supporters.
Forest were all at sea and had Danny Collins sent off for a rash challenge on the edge of the area a minute later.
From the resulting free kick, Latics' top scorer Jose Baxter sent home a measured low finish to complete a stunning turnaround at the City Ground.
Billy Sharp netted late on but it was merely a consolation for Forest as Alex McLeish slipped to a second successive defeat in charge of the Championship side.
