Oldham had a day to forget as Luton won the battle of two of the Second Division's form teams.
Latics went in front after only four minutes when fullback Dean Holden struck his second goal in consecutive games, running on to a pass from Tony Carss before sending a low cross shot into the bottom corner from 12 yards.
That, however, was as good as it got for the home side, who struggled to create chances for the rest of the game.
Luton were level in the 33rd minute as Aaron Skelton sent a long ball through for Andrew Fotiadis and the striker sent his shot between the keeper's legs.
Tony Thorpe sealed the comeback just before the hour mark when Chris Coyne headed down a corner and the little forward slotted in comfortably from six yards.
Luton's Matthew Spring almost made it three while their defence stood firm against what little Oldham had to offer.
Hatters boss Joe Kinnear said: "We had to work hard and came here with a depleted squad which makes the victory even better.
"The boys who came in and replaced the regulars did a very good job and I'm delighted that we had won away against one of the best teams in the division.
"Thorpe's movement was always a problem and I'm pleased he got on the score sheet because that's what I brought him to the club to do.
"That's four in four for Fotiadis who looked sharp and showed the Oldham defence a clean pair of heels."
HASH(0x9052c70)