While all the post-match talk was unfortunately about the crowd trouble that erupted towards the end of the match, the action that was produced on the pitch deserved to be the talking point after West Ham put in a really impressive performance against a Chelsea side who came into this EFL Cup fourth round match firing in all cylinders.
This was an important cup match for the Hammers, more to feel at home at the London Stadium than anything else, and for much of the 90 minutes, it did feel like that as the fans produced a cracking atmosphere, even if it all went downhill right at the end.
Cheikhou Kouyate opened the scoring for West Ham, with a ridiculously-good header in the 11th minute. Meeting a cross from James Noble, Kouyate somehow found the power and precision to find the back of the net from 16 yards out with his head, giving West Ham the much-required lead.
Both teams played with verve and panache going forward throughout the game and Chelsea will feel aggrieved by the fact that they could not find an equaliser before halftime.
That feeling would only increase when Edimilson Fernandes showed poise and technique to fire in a brilliant shot with his left foot into the Chelsea goal to give West Ham a 2-0 lead.
The Blues did their best to try and get back into the game, but Gary Cahill's close-range finish in stoppage time proved to be only a consolation.
"We played really good," West Ham manager Slaven Bilic, whose side will face Manchester United in the EFL Cup quarterfinals, said. "It was a great cup game, night game, London derby, and Chelsea are a great team who have hit great form recently.
"We had a game plan and the guys executed it almost perfectly. We were great in the first half and really good in the second half and when we had to defend, we defended in numbers and we were good at keeping the ball.
"In transition we hurt them and could have scored more. It was a great win and a great performance and it was good to beat Chelsea."
Antonio Conte, who made several changes to his starting lineup, was understandably disappointed with the result, even though not so much the performance.
"Usually you learn more after a defeat than a win but we must continue to work," Conte said. "I'm optimistic because I saw the right spirit and that's very important. You can lose or win but you must have the right spirit. If I see that, I see a clear future.
"Now we start to work for Sunday's game. We know we will play a very tough game against Southampton, who are in a good moment."