In-form striker Joao Pedro scored a second-half equaliser as Chelsea rescued a point at home to promoted Hull City.
The reigning Premier League Player of the Month curled a shot into the top corner in the 66th minute, but Chelsea were unable to find a winner.
Morgan Rogers had given Chelsea the lead in the seventh minute, but Hull went into the break ahead after Mohamed Belloumi scored twice.
Chelsea's opener arrived later than usual, having scored in the first, second and fourth minutes of their previous three league matches this season.
Club record signing Rogers, their £117m buy from Aston Villa, simply shifted the ball past Matt Crooks before firing a left-footed shot beyond goalkeeper Konstantinos Tzolakis - the first Premier League goal Hull have conceded this season.
The Blues then saw Pedro Neto flick an effort just wide before another curling shot was saved, but a lapse in concentration cost them the chance of a first Premier League clean sheet in 20 matches.
Left-back Jorrel Hato switched off to allow Mohamed Belloumi to volley in Ryan Giles' cross for a 28th-minute equaliser.
That swung momentum back in Hull's favour as Lewie Coyle forced a save with a low effort before Semi Ajayi headed against the crossbar.
After the ball ricocheted off the woodwork, striker Oli McBurnie reacted quickest to divert it into the path of Belloumi, whose shot found the net via deflections off Levi Colwill and Reece James.
Xabi Alonso brought on Pep Chavarria for Hato at half-time, but Chelsea struggled to break down Hull's defence, with Tzolakis forced into action only by an excellent James free-kick shortly after the restart.
In response, McBurnie saw a close-range effort brilliantly saved by Chelsea goalkeeper Emi Martinez after the Argentine had parried Regan Slater's shot from the edge of the area into his path.
But Joao Pedro smashed a left-foot equaliser into the near post after an impressive low cross from Palmer in the 66th minute.
Further edge of the box shots from Cole Palmer and James threatened to add a winner for Chelsea, while Rogers had the best chance saved by Tzolakis inside the box.
It was nearly all Chelsea late on as Estevao Willian and Danny Welbeck were among those brought on but Hull substitute Mohamed-Ali Cho had arguably the best chance to win the match in the 87th minute - his poorly struck shot was easily saved.
Hull remain third and Chelsea stay fourth in the table - having played a match more than half of the Premier League's sides.



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