David McGoldrick netted twice as Ipswich avoided a Carabao Cup upset at League Two Luton with a 2-0 victory at Kenilworth Road.
The striker fired past Marek Stech in the 35th minute before netting the clincher in injury time to ensure the Tractor Boys took their place in the next round.
Prior to the opener, Andrew Shinnie shot over the bar for Luton, while McGoldrick's impudent chip did not catch out home goalkeeper Stech.
James Collins' turn and shot was easy for Dean Gerken, before Ipswich had the lead courtesy of the impressive McGoldrick's confident finish.
Elliot Lee's curler just went wide as Luton searched for a leveller, while Myles Kenlock's low drive arrowed narrowly off target.
Town striker Lee should have made it 1-1 on the stroke of half-time, skying over from close range after Gerken could not hold Jordan Cook's low shot.
After the break, Stech made a smart stop from Jonas Knudsen's glancing header before Luton, who scored eight goals against Yeovil at the weekend, upped the tempo in search of a leveller.
First, Cook hit the side-netting after a one-two with Pelly-Ruddock Mpanzu and Scott Cuthbert was denied by Gerken.
New Ipswich signing Martyn Waghorn, who joined on Monday from Rangers, entered the fray and curled just wide in the 67th minute.
Stech touched over McGoldrick's deflected attempt, but Mick McCarthy's side made the game safe in stoppage time, with the striker coolly slotting into the bottom corner.