But, just as Bournemouth began mentally preparing for extra time, Alvaro Morata scored an injury time victor for the Blues.
Antonio Conte talks up the potential of Chelsea youngster Ethan Ampadu following his solid display against Bournemouth. "I have had good and bad times against them", he said, in quotes reported by the Evening Standard. If they deserve it, I'm ready to play with very young players.
On his second start since making his Blues debut against Nottingham Forest in September, the 17-year-old lasted for the entire duration as the 2012 European champions recorded a 2-0 win at Stamford Bridge.
"But if you look at what's happened over the last 10-15 matches between us, we have had good games too".
Chelsea led for most of their match against fellow Premier League side Bournemouth, but a late goal from Dan Gosling appeared to have the match headed to extra time.
Conte was speaking before the semi-final draw which means Chelsea and Arsenal will meet in the last four, and the Italian is keen to progress in the competition.
Morata will be back for Tuesday's Premier League clash at home against Brighton.
"It was important, because to go and to play 30 minutes more, I think it was a bit risky", Conte said. But he showed great maturity and personality.
"You have to play 93 minutes with this danger".
Chelsea play Everton at Goodison Park at 12:30 GMT on Saturday, 23 December.
"Maybe next game, he'll go to play for the youth league. We have to accept the decision and try, at the same time in the future, to pay great attention", he added.