Chelsea’s Premier League run of wins was extended to three games as Joao Felix’s first goal for the Blues was canceled out by Emerson in Saturday’s 1-1 draw.
Graham Potter’s expensively reassembled side failed to live up to their asking price as pressure mounted on the Blues boss.
Portugal striker Felix put Chelsea ahead on his second appearance for the club, only for Italian defender Emerson to trouble his former side with an equalizer before half-time.
Ninth-placed Chelsea have won just one of their past eight games in all competitions and are nine points behind the top four in the Premier League.
Chelsea, without a win in their last seven league games, spent more than £300 million ($362 million) on new signings during the January transfer window.
Although Potter insists he understands the pressure to get Chelsea back on track, the former Brighton boss can’t stop the rot and is sure to re-examine his tenure.
The Blues face Borussia Dortmund in the first leg of the last 16 of the Champions League on Wednesday and Potter will desperately need to steer his side into the quarter-finals to get some breathing room.
Failure to beat lowly West Ham was another black mark against Potter, with the east Londoners sitting just two points above the relegation zone.
Felix returned to Chelsea after a three-match suspension and the on-loan Atletico Madrid striker was an immediate threat when his goal was ruled out for a strict offside decision.
West Ham failed to heed the warning and Felix made them pay when they opened the scoring in the 16th minute.
– Chelsea stumbles –
It was a goal built by Chelsea’s new recruits, Mykhailo Mudryk pouncing on Jarrod Bowen before Enzo Fernandez curled a cross to Felix, who ran just right to beat West Ham’s offside trap on the rebound from six yards.
Chelsea took the lead in the first half with the type of display that they have struggled to put together this term.
West Ham finally threatened when Kepa Arrizabalaga blocked Michail Antonio’s heel effort from Bowen’s cross.
But Chelsea had lost focus and the lead was gone after 28 minutes.
It was a poor goal for Chelsea to concede as Vladimir Coufal was given too much time for Bowen’s cross to Emerson, who was left unmarked to scuff it in front of the far post.
Chelsea winger Noni Madueke, making his first start since joining PSV Eindhoven in January, almost restored their advantage, unleashing a fierce attack that was well saved by Lukasz Fabianski.
Fabianski made another good save to keep out Felix’s free-kick, while Antonio almost headed a Reece James free-kick into his own goal.
Chelsea struggled to find a rhythm in the second half and Potter sent on Mason Mount, Ben Chilwell and Hakim Ziyech.
West Ham thought they had won with eight minutes gone when Kepa pushed Declan Rice’s header towards Tomas Soucek, but the midfielder’s tap-in was disallowed for offside against Rice.
Conor Gallagher’s shot hit Soucek on the arm in stoppage time, but VAR refused to award a penalty.