Luton Town twice took the lead but eventually fell to a 3-2 home defeat as Chelsea advanced to the FA Cup quarter-finals on Wednesday night.
Played against a backdrop of Roman Abramovich confirming his intention to sell the club, Chelsea made a nightmarish start.
The Championship's second-highest set-piece scorers lived up to their billing as Reece Burke darted to the near post and glanced a corner with a pinpoint header, kissing off the far post before nestling into the net 102 seconds in.
Buoyed by a typically boisterous Kenilworth Road crowd, Luton, who made some changes of their own, pressed their rotated Premier League opposition high up the pitch.
However, it was the reigning world and European champions that capitalised upon a turnover in the opposition half. Saul Niguez crisply finished off a swift surge up the pitch following a cheap giveaway.
Luton's substitute goalkeeper Harry Isted - forced on inside 15 minutes for the injured Jed Steer - helped his side weather a bubbling squall of Chelsea pressure after their equaliser, making three impressive saves in rapid succession.
Harry Cornick fired the Hatters back into the lead against the run of play in the closing stages of the first half. Capitalising on Malang Sarr's failed attempts to catch him offside, Cornick showed no fear as he converted against the club he supported as a boy.
Chelsea had a monopoly of possession throughout but forced Luton back into their defensive third with a higher line in the second half. Nevertheless, their hosts' increasingly compact shape frustrated the Blues.
It took a delicate, lofted ball over the top from Ruben Loftus-Cheek to free Timo Werner behind the gaggle of orange and slot in a second leveller in the 68th minute.
As the game ticked into the final quarter of an hour, Werner went from scorer to provider, teeing up Romelu Lukaku to put Chelsea ahead for the first time all night.
Chelsea player ratings vs Luton Town
1. Goalkeeper & defenders
Kepa Arrizabalaga (GK) - 5/10 - Beaten by a pair of well-taken finishes.
Antonio Rudiger (CB) - 5/10 - Thrived in the physical duels on the ground but failed to make a discernible impact on Chelsea's repeated failures to combat Luton aerially.
Ruben Loftus-Cheek (CB) - 7/10 - It was an understandably mixed bag for the natural midfielder shunted into the back-three; not entirely assured when defending but increasingly commanding when striding forward in possession.
Malang Sarr (CB) - 2/10 - Left thoroughly embarrassed by his calamitous involvement in Cornick's goal and spent much of the match threatening to add another blunder to his reel.
2. Midfielders & wingbacks
Callum Hudson-Odoi (RWB) - 4/10 - Sloppily gave the ball away in the build-up to Luton's second goal and was predictable going forward.
Jorginho (CM) - 4/10 - Unsettled by Luton's aggressive pressure off the ball.
Saul Niguez (CM) - 7/10 - Took his goal superbly and was eager to pass and drive forward.
Kenedy (LWB) - 4/10 - In his first Chelsea appearance for four years, the club's forgotten man faded from this fixture as well.
Mason Mount (RW) - 7/10 - A regular menace dropping between the lines in central positions as Chelsea flooded midfield.
Romelu Lukaku (ST) - 6/10 - Ultimately in the right place at the right time in what was threatening to become another frustrating outing.
Timo Werner (LW) - 7/10 - Spent much of the opening hour timidly tip-toeing around the pitch before bursting into life with a game-changing goal and assist.
Harvey Vale (RW) - 6/10
Christian Pulisic (LW) - 6/10
Reece James (RB) - 6/10