A 94th-minute winner from West Ham defender Winston Reid nicked all three points for the Hammers in a 1-0 victory against Sunderland.
The Black Cats, still without a win this season, withstood an early Hammers onslaught and looked set to emerge with a point and a first clean sheet.
But, three-and-a-half minutes into the four added on, New Zealand defender Reid fired through a crowded penalty area to snatch West Ham’s second win at their new London Stadium .
Sunderland began the match so deep that the Hammers merely set up camp in their half and created four clear-cut chances in the opening 10 minutes.
Simone Zaza was close with two headers and Dimitri Payet curled one shot narrowly wide before the Frenchman slalomed through Sunderland’s defence and forced a fine save from Pickford.
Zaza, yet to score since his deadline-day switch from Juventus, was then sent through by Manuel Lanzini but Lamine Kone got back to make a crucial block and thwart the Italy striker.
Payet came even closer just before the half hour when he rifled a low shot through a crowded penalty area only to see it thump back off the base of Pickford’s post.
But Sunderland weathered that initial storm and began venturing into West Ham’s half, with Hammers old boy Jermain Defoe bringing the first save out of Adrian.
As the first half drew to a close Zaza met John O’Shea’s half-clearance with an acrobatic overhead kick but his effort flew wide.
West Ham had a major let-off moments after the interval when a defensive mix-up left Wahbi Khazri one-one-one with Adrian, but the Spanish keeper was out quickly to block his effort.
The hosts continued to dominate but their attacks became more desperate as the second half wore on, with Edimilson Fernandes snatching at his shot from the edge of the box and blazing over and Pedro Obiang hitting the side-netting.
Payet went on another mazy run but when he found Ashley Fletcher, and the substitute fluffed his return pass, many West Ham fans had seen enough and began heading for the exits.
Sunderland had, by then, decided to settle for a point and appeared to have done just that as the clocked ticked into injury time.
But Reid had other ideas when West Ham forced a late, late corner. Payet took it short, got the ball back and squared it to the centre-half, who in one fluid movement turned on the edge of the box and arrowed it through a crowd of players and past the unlucky Pickford.