ROVERS had every right to feel hard done by after they were sunk by Jason Koumas’ late double.
James Coppinger thought his drilled equaliser had earned Doncaster a deserved share of the spoils.
But Koumas came off the bench to stroke home a sublime 25-yard free kick in the last minute of normal time before latching onto Craig Bellamy’s pass to seal victory.
Chris Burke had given promotion chasing Cardiff the lead on 15 minutes when his shot - the visitors’ only meaningful attempt before the break - squirmed under the body of rookie keeper Gary Woods.
Doncaster, on the other hand, looked anything but a side still in danger of the drop and forced a string of saves from City stopper Tom Heaton.
Either side of Burke’s goal both Franck Moussa and Simon Gillett went one on one with Heaton but saw their shots saved, while Coppinger sent an effort fizzing inches wide.
The same pattern followed after the break as Heaton was at full stretch to deny Coppinger from range and then kept out Moussa’s downward header, while Woods did well to block Peter Whittingham’s close range shot at the other end.
Coppinger levelled when he latched onto James Hayter’s pass and arrowed a shot into the bottom corner - and the momentum appeared to be with the hosts.
But, in cruel fashion, it was the Bluebirds who had the final say.
Koumas, on loan from Wigan, curled in a free kick with his first touch to deny Doncaster a point.
And moments later, after a Cardiff counter attack, he stabbed a shot past Woods with virtually the last kick of the game to rub salt in Rovers’ wounds.