League One Oldham stunned Premier League high-fliers Everton with a deserved FA Cup third-round win.
Oldham's Gary McDonald celebrates his stunning strike at Everton
Gary McDonald's spectacular 25-yard strike seconds before half-time capped a superb display of resilience and effort from John Sheridan's side.
James Vaughan and James McFadden wasted early chances to put Everton ahead.
Oldham held Everton at bay with relative ease after the break, although substitute Yakubu hit the post with only seconds remaining.
Everton boss David Moyes made a host of changes and arguably could take a large share of responsibility for this massive shock.
Moyes's men started brightly, but their early attacking endeavours soon faded in the face of Oldham's stubborn resistance.
Steven Pienaar played in Vaughan in the opening minute, but the vastly experienced Oldham keeper Mark Crossley plunged at his feet to save.
McFadden then shot narrowly wide after a good link with Vaughan as Everton, sixth in the Premier League, pressed for an early advantage.
But Oldham played their way into the game and Craig Davies should have done better than mis-kick in front of goal after 27 minutes as Everton's reserve keeper Stefan Wessels struggled to collect a cross.
Wessels was then forced to dive to his left to save from Deane Smalley as Oldham enjoyed a period of supremacy.
But they survived an escape three minutes before the interval when McFadden's shot was smuggled away as Everton threatened.
And they took advantage in spectacular style on the stroke of half-time, when McDonald found time and space to send a dipping left-foot shot over Wessels.
Everton were making few inroads into the Oldham defence after the break and it was no surprise when Moyes made a double change on the hour.
Yayubu and Victor Anichebe replaced Vaughan and the disappointing Thomas Gravesen.
And it was Yakubu who came closest to rescuing Everton, firing against an upright with virtually the final kick of the game.
Everton: Wessels, Hibbert, Stubbs, Jagielka, Baines (Lescott 74), Pienaar, Gravesen (Anichebe 63), Carsley, McFadden, Johnson, Vaughan (Yakubu 64).
Subs Not Used: Ruddy, Anderson.
Oldham: Crossley, Eardley, Hazell, Stam, Lomax (Thompson 84), Smalley, McDonald, Kalala, Allott, Hughes, Davies.
Subs Not Used: Pogliacomi, Wolfenden, Alessandra, Black.
Goals: McDonald 45.
Ref: Uriah Rennie (S Yorkshire).
BBC Sport Player Rater man of the match: Oldham's Gary McDonald 8.12 (on 90 minutes).
Please note that you can still give the players marks out of 10 on BBC Sport's Player Rater after the match has finished.