Another game at the London Stadium and another poor result for Chelsea, making it only one win in four years at that ground. West Ham ran out surprise winners ending Chelsea's unbeaten run since the restart with a late winner courtesy of Andriy Yarmolenko.
In what could turn out to be a vital win for the Hammers, the Blues missed out on the chance to move into third place. Whilst they still remain in the Champions League places, there were still plenty of talking points to consider.
Therefore, without further ado, here are five things we learned from West Ham versus Chelsea.
1. Chelsea's Set Pieces Woes Continue
Another game and another set piece goal conceded from the Blues. A worrying statistic shows that from 109 corners faced, they've conceded 9 goals which is a conceded rate of 8.25%!
It is a poor stat and it was clearly on show in the game against West Ham. Before conceding from Tomas Soucek in first half injury time, he had a goal ruled out by VAR that came from as a result of a corner.
Chelsea fans can be particularly frustrated seeing their five foot 10 right back Cesar Azpilicueta mark the six foot four Soucek; it was never going to end well. What made it worse is that Tammy Abraham is six foot three and he was on the line instead of marking the tall defensive midfielder Soucek. Plus he failed to keep out the seemingly weak header on the line by not being able to sort his limbs out - to tell you the truth, I had no idea what he was doing.
It seems this is a real Achilles Heel for Frank Lampard's men, which is also down to the team not being extremely big in stature. These problems don't look like going away anytime soon.
2. Kepa Arrizabalaga Fails To Impress
The Spanish keeper has failed to impress this season boasting one of the worst shot to save ratio's in Europe's top five leagues. However, what really angered fans last night was his inability to have any sort of presence when it comes to defending crosses or balls into the box.
This point does tie in with the set pieces issue, but fans have sat and watched it happen all season. For me, his performances mirror that of a young David De Gea who came to the Premier League in 2011 and struggled to have any sort of impact in the air.
For the first goal, Kepa attempted to come out but looked more like a boy than a man when trying to collect the ball. Ultimately ending up in no mans land as the header trickled in. Chelsea fans are at their wits end when it comes the world's most expensive goalkeeper, and this hasn't helped his case at redemption.
3. Christian Pulisic Is Chelsea's Enforcer
When Eden Hazard left Chelsea in the summer (I do apologise for bringing that up) many were worried about who could take on the mantle of 'chief creator' Christian Pulisic arrived from Borussia Dortmund for a hefty fee, but was phased into the team by Lampard a little too slowly for the fans liking.
However, since the restart, he has been in tremendous form, scoring against Aston Villa, Manchester City and winning the penalty and free kick in which Chelsea scored from against the Hammers.
Gary Neville was quick to praise the American saying he was the best player on the pitch and likened him to his predecessor Hazard. His acceleration, chance creation and quality drove Chelsea's attack forward and he will be a key player going forward for the future.
4. Antonio Rudiger Should Not Be Starting
The Chelsea centre back dilemma will continue but after last night, German defender Antonio Rudiger received major backlash from fans and pundits alike. In my opinion, it was certainly warranted.
On the ball he looks shaky, he has no composure and is extremely rash. However the defining moment was just before half time, when he had the ball near the corner flag in his own half. Instead of clearing long or even for a throw in, he somehow skewed it out for a corner. Chelsea conceded from it and many fans were seething at him for doing something so stupid.
It isn't just this game, since he came back from injury halfway through the season, Chelsea have struggled defensively and while he offers the most experience, his defensive IQ and temperament is extremely questionable.
To top it off, for the final goal when faced with Yarmolenko, he allowed him to cut onto his left foot way too easily which resulted in the Ukrainian smashing in the winning goal. Everyone knows he is extremely left footed and was always going to cut in. Everyone except the German who's body positioning was all wrong. He didn't even attempt to show him onto his right foot and it just boils down to poor defending in what was a really poor performance.
5. Willian Still Offers That Quality
While there is much to be made of Willian's Chelsea career, he has to be said he has been a consistent performer in the squad this year. He has been trusted due to his experience and Chelsea's lack of a certified right winger.
Scoring the winning penalty against Manchester City and notching a penalty and free kick against West Ham showed he can still produce even with his time at Chelsea seemingly up.
It was a fantastic free kick against West Ham; almost a call back to his 2015/16 season, where he scored numerous free kicks. With players coming in next season, it seems this is his final year. However, he is throwing down the gauntlet to Lampard to be a part of the starting eleven until the end of the season.