Chaotic Chelsea ended a five-hour scoring drought before advancing in the FA Cup with a 5-3 penalty shootout win over Norwich.
The Premier League champions thought they had won for the first time in 2018 as Michy Batshuayi was on target in Wednesday night's FA Cup third-round replay at Stamford Bridge.
But Jamal Lewis headed in Timm Klose's cross in the fourth minute of stoppage time for 1-1 and force extra time, when Pedro and Alvaro Morata were sent off.
Pedro, earlier booked for diving, was sent off for a second bookable offence.