Alvaro Morata's stoppage-time strike sent Chelsea into the Carabao Cup semi-finals with a 2-1 defeat of Bournemouth.
Willian had given Chelsea a 13th-minute lead but the Blues invited pressure and Dan Gosling equalised in the 90th minute.
Chelsea attacked from the restart and Eden Hazard back-heeled into the path of fellow substitute Morata, who tucked in to send the Blues through.
The much-changed home side struggled to assert themselves against the Cherries but eventually prevailed, extending the visitors' winless run to seven games ahead of Saturday's trip to runaway Premier League leaders Manchester City.