A night to forget for Slaven Bilic and his West Ham United side after a last-gasp winner at Stamford Bridge but is there an underlying bigger problem?
Diego Costa's late winner proved to be the decider in what was a disappointing night for the Hammers, where they failed to get going in Antonio Conte's first game in charge.
We've seen his style during his spell in Turin with Juventus and the Italian national team - Conte likes a high-pressing and his teams play an intense game of football for 95 minutes, and the outcome showed that without key players West Ham are slightly short of the elite sides in the league.
Dimitri Payet, Manuel Lanzini, Aaron Cresswell and Sofiane Feghouli were notable absentees for Bilic and although Payet came on with 25 minutes left to play, without key players they lacked a spark.
For large spells, Chelsea were able to dictate the game on and off the ball. In possession the Hammers looked like they ran out of ideas, the ball into Andy Carroll was dealt with by John Terry and Gary Cahill time and time again, which meant that they had to play through the thirds but with N'Golo Kante, Nemanja Matic and Oscar shutting down space efficiently it showed that the need for a fit Payet and Lanzini is pressing for the way that Bilic wants them to play.
Chelsea's N'Golo Kante in action with West Ham United's Michail Antonio and Cheikhou Kouyate
Havard Nordtveit put in a solid performance and will be a welcome addition although with captain Mark Noble, they have two players looking to do a similar job - surely if they want to compete in the top seven they will need to add quality rather than quantity to complement the likes of Payet.
Bilic's men struggled to carve open a Chelsea rearguard that stayed compact and could only muster three shots on target and 38% of the possession, so it was no surprise that the goal came from a set-piece through a scramble in the box with James Collins in the right place to finish.
It wasn't a surprise that once star man Payet entered the fray, West Ham started to find some control and quality in the final third of the pitch, his presence on the field alone gives the rest of the side confidence.
No need to panic if you're a West Ham supporter, but the performance on Monday is evidence that the sooner they have their star players back the better.