Substitute Oussama Assaidi stunned Chelsea with a superb 90th-minute winner on Saturday as Stoke claimed its first league victory over the Blues in 38 years.
Stoke dented Chelsea's title drive with a 3-2 victory in the Premier League after on-loan Liverpool winger Assaidi came on six minutes from time and his first real contribution was to pick the ball up on the left, cut inside and unleash a ferocious shot into the top corner after being set up by Stephen Ireland.
Chelsea provisionally slipped to third on goal difference behind Liverpool.
The visitors led with a 10th-minute opener from Andre Schurrle who picked the ball up in midfield, held off Ryan Shawcross and Glenn Whelan before shooting across Asmir Begovic and into the bottom corner.
But Peter Crouch leveled three minutes before half time after a break instigated by Geoff Cameron, who found Jonathan Walters down the right. His cross was just out of the reach of Ireland but Marko Arnautovic won a corner and his delivery was turned in by Crouch.
Stoke carried the momentum into the second half and went ahead in the 50th.
Walters broke down the right and squared the ball for Ireland, who took one touch to control before curling a precision shot in off the far post.
A free kick by Juan Mata was half cleared by Crouch to Schurrle on the edge of the box, who once again produced a clinical finish into the far corner.
Schurrle almost completed his hat trick in the 57th but although he beat Begovic again his curling shot bounced off the bar.
Schurrle's hat trick hopes were ended as Mourinho sent on Frank Lampard and Samuel Eto'o, and the latter swiftly had a sight of goal but poked his shot just wide.
Stoke's last win over Chelsea came in the League Cup in 1995 when Potters manager Mark Hughes was in the Blues side, while their most recent league victory was in 1975.
The result ended Chelsea's three-match winning run.