Chelsea are through to the fourth round of the Carabao Cup but needed penalties to see of Dean Smith's resilient Aston Villa side.
Timo Werner had headed the hosts in front with his first goal in 11 appearances, but Cameron Archer fired back to level on 64 minutes.
Neither side could find a winner in 90 minutes, and Reece James struck home the crucial spot kick after Ashley Young and Marvelous Nakamba both missed for the visitors.
MORE TO FOLLOW
The Germany international rose highest to get on the end of Reece James's chipped cross to put the hosts ahead
Aston Villa fan Prince William (centre) celebrates the equaliser alongside the club's CEO Christian Purslow (left)
Trevoh Chalobah gets away from Aston Villa midfielder Emiliano Buendía as he looks to mount an attack for the Blues
MATCH FACTS
Chelsea (4-3-3): Kepa; James, Calobah, Sarr, Chilwell; Loftus-Cheek, Kante (Mount 46), Saul (Lukaku 76); Hudson-Odoi, Werner, Ziyech (Barkley 76).