Tammy Abraham struck a smart Stamford Bridge hat-trick as Chelsea drove past stubborn Luton with a 3-1 win and into the FA Cup fifth round.
England hitman Abraham took his Chelsea goal tally to 11 for the season, netting twice in seven first-half minutes before completing his treble late on.
Jordan Clark profited from the struggling Kepa Arrizabalaga's latest error to claw one back for Championship side Luton, but the Blues ground their way to an important fourth-round win.
Timo Werner missed a late penalty in a frustrating end to his afternoon, but Chelsea will now travel to Barnsley in the fifth round.
This victory was crucial for under-pressure boss Frank Lampard, who will now set about trying to engineer a return to winning ways in the Premier League.
Relive all the latest FA Cup action as it happened with James Robson on our LIVE match blog.