Marcos Alonso's extra-time goal gave Chelsea a 2-1 win over Plymouth Argyle in the FA Cup fourth round at Stamford Bridge on Saturday, despite the visitors being given a late penalty.
Chelsea were without head coach Thomas Tuchel after he tested positive for COVID-19 a few hours before kick-off and they needed 120 minutes to edge past their League One opponents.
The hosts had three attempts at goal in the opening five minutes but it was Plymouth who opened the scoring, with Macaulay Gillesphey flicking in a header from Jordan Houghton's curling free-kick after seven minutes.
Chelsea dominated the remainder of the half but hit the woodwork three times before Cesar Azpilicueta finally found an equaliser in the 39th minute.
The frustration continued for Tuchel's side after the break, with a couple of stunning saves from Plymouth goalkeeper Michael Cooper keeping the score level and taking the game to extra time.
It took until the 106th minute for Alonso to find Chelsea's winner, sliding in a first-time finish from a Kai Havertz cross.
Plymouth had a chance to equalise with two minutes to go after Ryan Hardie was awarded a penalty, but the striker's attempt was saved by Chelsea goalkeeper Kepa Arrizabalaga to take his side into the fifth round.