After felling Nottingham Forest (3-0) prior to the international break, there was little hint of what was to come as the Hammers marked their return to action with a gritty, yet goalless, opening 45 minutes against Thomas Frank’s visitors.
But everything changed for the worse after the interval as Pape Matar Sarr, Lucas Bergvall and Micky van de Ven each netted to secure a 3-0 victory over Graham Potter’s sorry side, who were reduced to ten men after Tomas Soucek was sent off with over half an hour remaining.
"The first half was even - we had good attacks and good moments, which was positive for us," insisted the Hammers head coach.
"We were also solid from a defensive perspective and didn’t give many chances away, while we dealt well with their set pieces, too.
"Our fans were with us at half-time.
"They were really there.
"They appreciated the fact we were in the game and they’d seen a committed, positive performance from a team making some good attacks but after that second half, everything feels negative."
Those supporters were still returning to their seats, when debutant Xavi Simons - a £52million signing from RB Leipzig – whipped over a deep corner to the far post, where the unmarked Sarr nodded home.
Then, on 54 minutes, Soucek was dismissed for a reckless, raking tackle on João Palhinha, whose ripped sock gave referee Jarred Gillett all the evidence he needed to produce an instant red card.
And with the red-faced Czech Republic midfielder still trudging down the tunnel of shame, the consequent free-kick was worked upfield towards Bergvall, who sent a looping 18-yard header over the stranded Mads Hermansen.
The hesitant Hammers keeper again found himself picking the ball out of his net midway through the second period after van de Ven secured the victory that sent Spurs into third spot.
"We made a mistake to concede their first goal," observed Potter.
"We’re talking fine margins at this level and we got punished.
"Then, the red card came along and although there was no intent or speed in Tomas’ challenge, if you raise your foot there’s going to be a potential problem."
With a car park blaze already causing a full-scale evacuation at nearby Westfield Shopping Centre, it certainly looked like a similar fire drill was underway at a rapidly emptying London Stadium, too.
"I get the fans’ frustration and reaction at seeing the scoreline run away from us so quickly after the red card and it all made for an uncomfortable evening – I’m really disappointed and feel for the players and the supporters.
"We’d had a good result at Nottingham Forest but I can understand why there was that feeling today."
With a fan protest planned at Saturday’s match against Crystal Palace (kick-off 3 pm) things are unlikely to get any easier down West Ham way any time soon.
"It’s been tough and, although I don’t think there’s a problem playing here, our home form hasn’t been good for a period of time," conceded Potter whose 18th-placed Hammers have now gone seven matches without a win at London Stadium - a wretched run stretching back to early March.
"That’s something we have to try to change and we’ve got to deal with it by focusing on the positive things, playing well and winning."