David Friio and Micky Evans snatched a barely-deserved victory for Plymouth Argyle with a goal apiece in the last seven minutes.
Luton will count themselves unfortunate not to become the first side to win at Home Park since last Spring after taking the lead early in the second half through Gary McSheffrey.
Luton were pegged back when Friio set David Worrell free on the right to send in a cross that Evans headed home, for his fourth goal of the season, at the near post.
Argyle stole a victory against their bitter rivals from the 2001/02 Third Division championship race a few minutes later when Friio's flicked header from captain Paul Wotton's inswinging free-kick deceived young goalkeeper Rob Beckwith.
Argyle also had a rookie goalkeeper in Luke McCormick, a replacement for Frenchman Romain Larrieu, who seems set to miss a large part of the season after damaging his knee ligaments at Brentford the previous week.
McCormick, though, had a good game and was not to blame for McSheffrey's goal, a header from six yards following Kevin Foley's cross after Plymouth never recovered from Wotton's failure to clear.
Apart from that goal, the dramatic closing, and a third-minute goal-line clearance by Plymouth's Graham Coughlan from David Bayliss' header, there was little for the crowd of nearly 10,000 to get excited about.