Madueke scores his second goal in two games, following a midweek winner against Crystal Palace.
Chelsea looks dominant with a 3-0 lead in the 70th minute.
Luton Town makes a late fightback with goals from Ross Barkley and Elijah Adebayo.
Chelsea coach Mauricio Pochettino warns about the unpredictability of the Premier League, while Luton coach Rob Edwards praises his team's resilience despite the loss.