Carney Chukwuemeka and Noni Madueke struck twice in added time to fend off a Leicester fightback as Chelsea reach the FA Cup semi-finals.
Marc Cucurella had opened the scoring in the 13th minute, with the in-form Cole Palmer doubling the lead in added time of the first half after a shocking penalty miss from Raheem Sterling.
Despite being 2-0 down at the break, the Foxes fought back to level by 62 minutes, with Axel Disasi putting the ball into the back of his own net before Stephy Mavididi made it 2-2 with a brilliant solo effort.