Late strikes from substitutes Ben Chilwell and Kai Havertz ensured three points for big-spending Chelsea in their Premier League London derby with West Ham on Saturday afternoon, but Thomas Tuchel's side certainly didn't have it all their own way in a pulsating second half at Stamford Bridge.
Chelsea entered the match on the back of a transfer window which saw them smash the Premier League record for the most money spent in a single summer in English top flight history as new owner Todd Boehly looks to make a statement in the early days of the post-Abramovich era in West London.
Of the galaxy of new signings made by the club, Raheem Sterling, Kalidou Kouliblay, Marc Cucurella and Wesley Fofana were named in the starting lineup - but even with a collective price-tag somewhere north of £215 million ($264 million) Chelsea couldn't shift out of third gear in a tepid first half during which they enjoyed the lion's share of possession but failed to carve out a single shot on target.
West Ham were proving to be frustrating foe for Chelsea as they pressed in the second half and made the breakthrough on 62 minutes as Michail Antonio poked home from close range after Edouard Mendy flapped at a corner.
It was the latest mixup from a corner from Chelsea's backline this season in what is becoming a worrying trend for Tuchel and his set piece guru Anthony Barry, and looked to be sending the Blues to their third defeat in four games.
Tuchel retaliated, sending both Chilwell and Havertz into the game shortly after Antonio's goal - and Chilwell almost immediately rewarded the German coach when he levelled the scores with a neat goal from a tight angle on the left.
Less than ten minutes later Chilwell turned creator as he crossed for Havertz to blast the ball home from close range to make the score 2-1 on 88 minutes.
The drama was far from over. Just two minutes later, West Ham's new signing Maxwell Cornet looked to have equalized only for the referee to rule out the goal after viewing VAR footage, determining that there was a foul on Chelsea goalkeeper Mendy in the buildup, much to the obvious chagrin of Hammers boss David Moyes who furiously remonstrated with the officials when the final whistle was blown.
“It is super tough to score against West Ham, they defend deep and with bodies - the game became more complicated with the goal we gave away,” Tuchel said afterwards.
“It was a huge effort to come back and huge credit to the team, the impact from the bench - full credit to everybody.
“It was a clear foul on the goalkeeper, I had doubts about the first one - but I will not comment, last time I got punished with huge fines. You give your opinion, you will not be fined.
“It was not easy to keep the belief, it is hard to attack fluid and create chances against West Ham, nobody plays an open, spectacular match against them.
“We take it now step by step, we will try to use this momentum - things are clear now, we can demand full commitment to everything. We are in the middle of creating this and it is not finished.”