Raheem Sterling's double and a goal from Nicolas Jackson gave Chelsea their first Premier League win under manager Mauricio Pochettino as they saw off Luton at Stamford Bridge.
Sterling, who has started the season in excellent form, picked the ball up wide on the right and jinked his way through three players before firing into the bottom corner in the 17th minute.
The England winger then doubled Chelsea's lead in the 67th minute when he scored from close range from a Malo Gusto cross.
Sterling was involved again as Chelsea got their third, sending a low cross into the area for Jackson to score his first goal for the club.