Paul Ince’s side drop from 46 points to 40, which leaves them hovering just a point above the bottom three.
Unsurprisingly, odds on the Royals being relegated to League One have since been slashed by bookmakers.
Here’s the latest odds according to Casinos En Ligne...
5. Huddersfield Town - 6/4
Neil Warnock's side, who have won their last two, are level on points with Cardiff. Photo: CameraSport - Dave Howarth
6. Reading - 5/4 (was 8/1)
Odds have now been slashed on Reading to be relegated following their six-point deduction. Photo: CameraSport - David Horton
7. Blackpool - 1/4
Mick McCarthy's side currently sit second bottom, four points adrift of safety. Photo: CameraSport - Alex Dodd
8. Wigan Athletic - 1/5
The Latics sit bottom on 34 points after being hit with a three-point deduction. Photo: CameraSport - Andrew Vaughan