Reece James scored the winning penalty in a shootout as Chelsea reached the last 16 of the Carabao Cup at Aston Villa's expense.
The full-back fired home the Blues' final penalty to win the shootout 4-3.
A goal from young Villa forward Cameron Archer had ensured a draw in normal time, levelling with a header after Timo Werner had put the Blues ahead.
Chelsea will host Southampton in the last 16 of a competition they last won in 2014-15.
Wednesday's result extends the reigning European champions' unbeaten start to the season, which has also seen them top the Premier League with 13 points from five matches.