Chelsea spurned the chance to go within a point of 2nd place in the Premier League following a frustrating 1-1 draw with Southampton at St Mary's Stadium.
The Blues were asked questions by a disciplined Saints defence, yet never provided the answers, failing to get out of second gear as they had to come from a goal down to rescue a point.
Takumi Minamino was gifted acres of space between the Chelsea centre halves and remained composed to put Southampton ahead in the 33rd minute.
The away side came out with better intent in the second half and were rewarded when Mason Mount was hacked down by Danny Ings in the 18-yard box. The victim of that challenge stepped up and slotted the ball home to restore parity in minute 54.
Beyond a good effort from the same source and a tame attempt from a lacklustre Reece James, the Blues never kicked on as both sides played out the draw.
After a performance characterised by a lack of cutting edge and a worrying lapse of concentration at the back, there will be much for Thomas Tuchel to chew on before the trip to face Atlético Madrid in the Champions League on Tuesday.
Edouard Mendy - 5/10
Restored to the line-up after Spanish counterpart Kepa Arrizabalaga kept consecutive clean sheets. On the one occasion he was really needed, he failed to make himself big for the Saints opener and went to ground too early.
César Azpilicueta - 5/10
The skipper will be beating himself up over losing the darting run of Takumi Minamino from his flank, but at least busted a gut to try and prevent the goal. Beyond that costly lapse, he went about his business with minimal fuss.
Antonio Rüdiger - 6/10
Was the most solid of the Chelsea backline, albeit not the most difficult achievement. Fancied his chances with a tame shot from 30 yards that was born of frustration.
Kurt Zouma - 4/10
Thomas Tuchel handed the 26-year-old his first league start under the new administration and the Frenchman did himself no favours. Left the gap in behind as he was caught ball-watching for the Southampton goal, and then made little to no effort to recover. Had a chance to make instant amends with a diving header, but looked unnatural at the heart of defence.
Reece James - 4/10
Played a few menacing balls in the first quarter of the match, including a wonderful looped cross to Marcos Alonso. He was far too casual and ineffectual thereafter, due in no small part to a surprising lack of click between him and long-time teammate Mason Mount. Lazily spurned a glorious chance in the dying embers, and the jury is out on his impact in the wing-back role.
N'Golo Kanté - 6/10
A real Jekyll and Hyde performance from the veteran midfielder. Was initially a bundle of energy in his first league start of the Thomas Tuchel reign. Covered every blade of grass of the St. Mary's pitch, consistently regaining and recycling possession for the Blues with his interceptions and tackles. Looked tired as the game wore on, indicative of being short on match fitness.
Mateo Kovačić - 5/10 
After the heights of Newcastle, this was a poor performance from the Croatian. Seemed laboured in possession with less of the zip and intensity that has been on display in the past month. Looks more comfortable alongside Jorginho, who he was substituted for late on.
Marcos Alonso - 6/10
Found himself in space with regularity and perhaps should have done more with it. Snatched at a volley in the first half that he would be fancied to score on most occasions. His burgeoning relationship with Timo Werner promises returns on another day. Moussa Djenepo had more success against the Spaniard late on.
Mason Mount - 7/10
By his standards, a complete passenger until he was sliced down by Danny Ings in the penalty area. Promoted to penalty duties with Jorginho on the bench, he dispatched it with a coolness beyond his tender years. Looked reinvigorated afterwards and forced Alex McCarthy into a full-stretch save with a delicious effort. Led by example in the second period.
Timo Werner - 6/10
His pressing in the early stages was relentless as he closed down the Southampton backline with confidence. His workrate was perhaps only bettered by N'Golo Kanté, but it did not quite fall his way today.
Tammy Abraham - 4/10 
Worked hard up front after shaking off the knock he took against Newcastle earlier in the week, but barely got a sniff of the ball up against the low block. Will be disappointed he was a non-factor and needs to offer more in his attacking positioning, or else this reoccurence of being hooked at half-time will persist.
Callum Hudson-Odoi  
Hakim Ziyech