Chelsea crashed to their fourth league defeat in five as they rightly fell foul to a late VAR decision, as Bournemouth scored the only goal at Stamford Bridge this afternoon.
This was an abject performance by the west Londoners who could claim to have had one clear-cut chance - an Emerson point-plank header well saved by Aaron Ramsdale.
It was left to Dan Gosling six minutes from time to beat the offside trap and hook the ball into the Chelsea net. Not even a vain effort by Cesar Azpilicueta, who hooked the ball away could alter the decision by VAR, who after seeing the linesman claim Gosling was offside, told referee Graham Scott a clear mistake was made.
That killed off the Chelsea players - who it has to be did not deserve anything from the match.
Ryan Fraser forced Kepa into a fine near post save after three minutes as the visitors played, clean, controlled, passing football.
Mason Mount, on eight minutes, latched onto a cute ball by Willian, chested the ball down and in one movement slammed a goal-bound right-footed volley - but Aaron Ramsdale was equal to the task and smothered the effort.
Tammy Abraham tried a near-post slicer and a header on the stroke of half-time that went sailing over the crossbar.
There were no changes by either side at half-time.
The second half. Started as much of the first ended, with the Blues looking disjointed in attack and vulnerable in defence, especially on Bournemouth’s counter-attacks.
Head coach Frank Lampard decided on 65 minutes to replace Christian Pulisic for Mateo Kovacic and Willian for Callum Hudson-Odoi.
The expression point-blank save can but overused, but on 73 minutes, Emerson was four yards out but sent his header straight into Ramsdale. It was an incredible miss by the left-back as the Blues sought to take advantage of the extra pace and power brought by the substitutes.
Ex-Blue Dominic Solanke entered the fray with 14 minutes left - replacing injured Joshua King.
Michy Batshuayi took off Jorginho on 78 minutes.
Sensationally the visitors took the lead with five minutes left on the clock. A regulation header into the Chelsea area, was met by a hooked effort by Dan Gosling.
The ball looped goal wards - Cesar Azpilicueta hacked it clear, but it had gone over the line.
VAR intervened after the linesman gave Gosling as offside, but the VAR judge, Simon Hooper rightly judged Gosling was onside and the referee Graham Scott pointed to the centre-spot.
Next up for Chelsea is a trip to Spurs, who could leapfrog the Blues - something Spurs boss Jose Mourinho will be more than aware of.
Teams: Chelsea, Arrizabalaga, Rudiger, Jorginho, Kante, Abraham, Willian, Zouma, Mount, Pilisic, Azpilicueta, Emerson
Subs: Christensen, Pedro, Kovacic, Hudson-Odoi, Batshuayi, James, Caballero
Bournemouth, Ramsdale, Francis, Gosling, King, Lehman, Cook, Stacey, Rico, Fraser, Billing, Mepham
Subs: Boruc, Surman, Solanke, Stanislas, Simpson, Kilkenny, Dobre
Referee: Graham Scott