Twenty-five minutes had gone on Saturday afternoon in London, and all was well. At around 12:55 p.m. at the Olympic Stadium, West Ham was buzzing about its home pitch. Flying into tackles. Charging forward. Pressing. There was the occasional warning sign, sent by the visitors, Tottenham, but nothing more.

On 27 minutes, a muscle in Michail Antonio’s left leg went, and everything changed.

On came Andy Carroll, off went West Ham’s rhythm, and sure enough, 10 minutes later, Spurs were 2-0 up and in the clear. They were 3-0 up after an hour.

Serge Aurier’s second yellow card made for a nervy and temperamental final 20 minutes. Javier Hernandez and Cheikhou Kouyate brought West Ham back into the game, and Carroll howled for a penalty in stoppage time. Multiple scuffles broke out as the London derby came alive. But Tottenham got the three points it deserved.

And in the end, that was in large part thanks to Carroll.

It’s not quite that simple, but it’s not overly complicated either. Slaven Bilic stuck Carroll up top, pushed Hernandez wide, and West Ham inevitably altered its approach. The magnetic pull of Carroll’s stature and aerial prowess was too strong. And that was precisely the problem.

When Carroll found the ball in midfield several minutes after his introduction, West Ham’s spacing was awkward at best. Carroll miscued a square pass to nobody in particular, and Tottenham’s attacking trio of Christian Eriksen, Dele Alli and Harry Kane took advantage of the mistake:

Four minutes later, West Ham again played long to Carroll. This time, he didn’t even get on the ball. His lazy challenge for Joe Hart’s clearance ignited Tottenham’s break for its second:

Prior to the substitution, West Ham had been pumping balls in behind Tottenham’s back line for its front three to chase. Once or twice, those balls were successful. Had Marko Arnautovic’s final-third decision making been better, they might have even yielded a goal.

But the key was that those long balls were never unsuccessful. At the very least, they propelled West Ham out of its own half. The territorial battle was evenly contested.

Then Carroll came on, and suddenly, those long balls stopped going in behind. They started going to the big English target man. And when Carroll lost them, West Ham’s high defensive line was exposed.

Tottenham’s dominance continued after the break, with Kane, on a hat trick, striking both posts, and Eriksen putting Tottenham 3-0 up:

Hernandez, in typical Javier Hernandez fashion, pulled back a goal by sneaking into space at the far post and pouncing on Jose Fonte’s flick. At the time, it felt like nothing more than a consolation:

And it still felt like nothing more than a consolation with five minutes remaining, even after Aurier was dismissed. But Kouyate’s goal made for a lively final two minutes, and then six of added time.

Spurs, in the end, held on, and coped fine 10-on-11. Aside from last weekend’s blip at Swansea, Mauricio Pochettino’s men appear to be rounding into form.

And even when they’re not firing on all cylinders, all Kane, Alli and Eriksen need are slivers of space and opportunity. West Ham presented them with just that. And the Hammers were punished.

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Henry Bushnell covers soccer – the U.S. national teams, the Premier League, and much, much more – for FC Yahoo and Yahoo Sports. Have a tip? Question? Comment? Email him at henrydbushnell@gmail.com or follow him on Twitter @HenryBushnell.