Sunderland suffered heartbreak at the London Stadium as Winston Reid secured three points for West Ham United with the penultimate kick of the game.
Michail Antonio and Dimitri Payet led the charge for the Hammers who went close on countless occasions during the opening 25 minutes, but from that point forward they were unable to find a way past the Black Cats.
England under-21 international Jordan Pickford starred for the Black Cats, producing a brilliant save to deny Payet, who also struck the post, as he went within seconds of a first senior clean sheet.
Wahbi Khazrri spurned Sunderland’s best chance as David Moyes’ side raced out of the blocks following the restart, and they were punished so, so late as their resilient defences were finally breached by Reid in added time.
Sunderland made two changes ahead of the game restoring Lamine Kone and Steven Pienaar to the starting XI, with Papy Djilobodji and Paddy McNair dropping to the bench.
Jermain Defoe led the line against his former club.
At the other end, Simone Zaza was tasked with spearheading the attack, and the Italian almost opened the scoring with just two minutes on the clock.
Antonio crafted the move after being allowed time and space on the right, but despite towering above the Black Cats defence Zaza was denied as Kone diverted the ball behind.
Moments later Payet sent a trademark effort whistling wide of the post, with the Hammers denied two penalties during the opening ten minutes as John O’Shea grappled his man before Javier Manquillo brought down Reid.
Chances continued to fall for the Hammers in a frantic opening act as Payet weaved into the box and fired at Pickford, but Antonio continued to provide the main source of creativity as the Black Cats failed to get to grips with the wing back.
Sunderland somewhat weathered the storm in the passage that followed and they enjoyed more time on the ball, but Slavan Bilic’s side remained in the driving seat.
A dazzling effort from Edmilson Fernandes cannoned off Kone before Payet produced another magic moment, but again the Frenchman was denied as the post came to Sunderland’s rescue.
The Black Cats’ brightest spell came following the half-hour mark with Manquillo winning a dangerous free-kick before Jack Rodwell headed wide.
Adrian was also forced into action to block a low cross from Pienaar after fine work from Duncan Watmore, with Defoe wriggling free seconds later before sending a weak effort towards goal.
And it wasn’t until added time that the visitors were troubled again, with Zaza’s spectacular bicycle kick flying inches wide.
Within 60 seconds of the restart, Sunderland should have led.
West Ham sloppily gave the ball to Pienaar in the centre of the park and he slide the ball towards Khazri – taking a deflection to bamboozle the home defence – but after shifting the ball onto his right foot the Tunisian was denied one on one.
The opportunity provided the sell-out away support a lift, and the traveling red and white army were on their feet again moments later as Defoe fired over the crossbar.
Like Khazri, Zaza was provided with an opportunity to run at goal, but Kone simply brushed the Italian off the ball to set the tone for the following segment of the game.
The Hammers were frustrated and the Black Cats went in search of an opener, but the tide turned on the hour mark and all of a sudden it was the home side piling forward.
But, like the Black Cats, they simply couldn’t hit the target with Fernandes blazing over meaning Pickford remained untroubled since an early onslaught.
West Ham arguably had the better of the exchanges in the closing stages but Sunderland battled and they were resilient from back to front, and they went within a whisker of a point they deserved.
But right at the death, when chances of a winner for either side looked gone, Reid rifled the ball through a crowded area and into the net to break Wearside hearts.
Sunderland: Pickford, Manquillo, van Aanholt, O’Shea, Kone, Rodwell, Ndong, Pienaar (McNair, Watmore (Gooch 75), Khazri (Jones 86), Defoe.
Substitutes: Mika, Anichebe, McNair, Honeyman, Djilobodji, Gooch.