Mick McCarthy blasted his players following the FA Cup defeat by Brentford at the weekend, but this abject defeat was just as humiliating as Boro ran riot from the outset.
First-half goals from Emanuel Pogatetz and Stuart Parnaby left the home side with a mountain to climb and a stunning strike from Jimmy Floyd Hasselbaink midway the second period killed off all hopes of a possible comeback.
Sunderland welcomed back central defender Steve Caldwell from suspension and on-loan striker Anthony Le Tallec was preferred to Kevin Kyle, who made his first appearance for 17 months at Griffin Park, while Boro, without eight first-team players, were thankful Gareth Southgate passed a late fitness test.
The warning bells had been ringing loud and clear for the Black Cats in the early stages with Boro on top from the outset causing the home defence endless problems and restricting the home side's attack to non-existent.
Boro missed a great chance in the first minute, Doriva failing to pierce the defensive wall from an 18-yard free-kick and Hasselbaink firing over the bar after a strong run from Mendieta.
The persistence of Justin Hoyte set up a chance for Le Tallec who failed to hit the target in a rare home attack before Boro surged ahead after 18 minutes.
Dean Whitehead was penalised for handball and when Stewart Downing curled the free-kick into the penalty area Pogatetz sent a looping header goalwards and to the dismay of the home fans over the grasping hands of Kelvin Davis.
There was no doubting the quality of the second goal though in the 31st minute. Parnaby galloped down the right and when Mark Viduka cleverly held the ball up with his back to goal, Parnaby took the return pass in his stride to leave Davis helpless.
Black Cats boss Mick McCarthy responded by taking off defender Danny Collins and throwing on Kyle and the move should have paid dividends in the 38th minute when a knockdown from the substitute found Jonathan Stead, who fired wide from a great position.
Stead fared no better after the break, again failing to hit the target from a great position but the chance fell to Whitehead in the 59th minute.
A clever back heel from Stead set up Whitehead but from less than six yards the Black Cats' leading scorer blazed over the bar.
Sunderland continued to hoist high balls in the direction of Kyle, but they were given a lesson in finishing in the 71st minute. Tommy Miller lost possession allowing Mendieta to slip the ball through to Hasselbaink, who quickly dispatched a crisp drive past a bewildered Davis.
Sunderland fans deserted in their droves, venting their frustration in their wake as relegation becomes more inevitable by the game with time fast running out for McCarthy to turn the tide.