A raft of halftime changes, including the introduction of Reece James and Marc Cucurella appeared to swing the game back in Chelsea's favour after a listless first half.
Enzo Maresca's selection raised eyebrows pre-game, as the youngster Jorrel Hato and the returning Wesley Fofana were preferred to James and Cucurella. Chelsea looked toothless in attack, failing to record a shot on target until the 43rd minute of the game.
The Blues also looked unorganised in defence, with Tosin Aradarobioyo and Nathaniel Chalobah leaving each other high and dry after stepping out of the back line and failing to secure possession. It was Chalobah to blame for Brentford's opener, as he rushed into the Bees half, failed to dispossess Igor Jesus, allowing Jordan Henderson to spray a raking ball over the top for Schade to run on to. The German midfielder duly slotted past Sanchez, who was unsighted by the lunging tackle of Tosin.
The introduction of James and Cucurella jogged Chelsea into life, but it was the 56th minute appearance of Palmer that was the telling intervention. Joao Pedro, who looked starved of service in the opening half, won a knockdown from Enzo Fernandez's cross, allowing Palmer to calmly slot home the equaliser.
A reinvigorated Chelsea attack hammered away at Brentford's resolute defence. Just as it looked like the Blues would have to settle for a point, Moises Caicedo rattled home a rasping effort from the edge of the box.
However, the drama was not over, as a long throw into the box by Schade fell to Carvalho, who converted past a despairing dive by Robert Sanchez.
