Sam Allardyce got his tactics spot on as the east London side came to White Hart Lane and outplayed Tottenham for a full 90 minutes.
They never looked in danger as Cheikhou Kouyate put the Hammers 1-0 up before Diafra Sakho doubled their lead.
Another victory at Tottenham - the side Allardyce has enjoyed the most wins against during his managerial career - looked secure and three vital points looked to be headed West Ham's way.
It seemed cruel - certainly for West Ham - as Danny Rose somewhat fortuitously struck before Harry Kane tucked home the rebound from a penalty he missed in injury time.
And no one personified the east London side's agony better than shot stopper Adrian.
The Spaniard, usually so reliable for West Ham, was at fault for Tottenham's first goal and came so close to preventing their second. He saved Kane's initial penalty but could only look on in frustration as the 21-year-old netted at the second time of asking.