The 18-year-old academy star revealed he only learnt he would be in the starting XI yesterday afternoon.
He told Chelsea TV: "I was a bit nervous but, in the game, I was feeling okay."
Manager Roberto Di Matteo made seven changes in all, including recalling Ryan Bertrand at left-back.
The rising star responded with his second goal of the season and said afterwards: "The year just keeps getting better for me so as long as I can keep it going I should be able to do good things.
"We want to keep it going and hopefully repeat the success we had last year.
"The manager is utilising the squad and rotating it very well, and he chooses the players who can be effective in every game."