For the best part of an hour, Preston performed in a manner that suggested Stamford Bridge could be the scene of some FA Cup magic.
Then Chelsea flexed their muscles and quickly killed off that prospect with three goals in 11 tie-ending minutes before adding a late fourth.
It was looking tricky for Chelsea as they struggled for a long while to break down Ryan Lowe's Championship side.
They were impressive and Chelsea the opposite.
But their four-goal margin of victory in the end made it an ultimately comfortable win and ideal start to an important few days in the cup competitions which represent Chelsea's best chance of success this season and getting into Europe next term, which the hierarchy are expecting.