Stoke's hope of gaining promotion took a major setback with a heartbreaking loss at the hands of Cardiff.
Gudjon Thordarson's side made the visitors fight all the way but Cardiff's defence held out almost to the end under a barrage of pressure.
Cardiff started brightly when Leo Fortune-West turned to shoot from eight yards but missed the ball in the first minute to let Stoke off the hook.
Chris Iwelumo then tried his luck when the ball fell to him after a scramble but he could only fire high and wide of the left-hand post.
Cardiff's third attack then resulted in a goal when Robert Earnshaw slotted the ball underneath Neil Cutler from 14 yards in only the 12th minute.
Marc Goodfellow did well on the left to play a deflective cross into the path of Bjarni Gudjonsson who attempted a cheeky volley into the top corner but failed to hit the target in the 21st minute.
Cardiff looked for a second in the 29th minute when Mark Bonner floated the ball back into the box where Fortune-West rose but hit the bar.
The second half saw the Potters fight harder but Cardiff weren't letting go of their lead.
Sergei Shtanyuk spread the ball right in the 31st minute for Wayne Thomas to dart into the box and fire a warning shot that Neil Alexander was equal to.
Stoke came forward again five minutes later when James O'Connor hit a right-footed drive from 18 yards that Alexander could only parry to his left at full stretch. The Bluebirds added a second in the 59th minute when a deflection off a Spencer Prior header hit the woodwork and was fired home by Fortune-West from six yards.
Eager Cardiff attacked again in the 75th minute when too much space in the Stoke box allowed Earnshaw to have a shot but Cutler saved superbly with his legs.
Super sub Deon Burton gave Stoke a lifeline when O'Connor's cross found him at the back post for him to hammer a shot into the roof of the net from six yards in the 84th minute.
There was another heart stopping moment on the final whistle when a Thomas cross found Burton again for him to head past Alexander but failing to beat the defenders on the line.
Stoke now have to go away to Cardiff and try to graft out a victory which would ensure them a place in the final