Manchester United did enough to see off Luton in their Carabao Cup third-round clash at Kenilworth Road but it was another laborious display from Ole Gunnar Solskjaer’s side.
A Juan Mata penalty on the stroke of half-time and neat finishes from substitutes Marcus Rashford and Mason Greenwood secured a largely unspectacular 3-0 win.
After slipping to a home defeat to Crystal Palace on Saturday, Solskjaer made 10 changes in Bedfordshire, although his starting line-up still boasted eight senior internationals.
Donny Van De Beek made his full debut in midfield, while goalkeeper Dean Henderson finally made his Manchester United bow, with Rashford required off the bench to sew up the victory.
A trip to Preston or Brighton awaits in round four, but Solskjaer knows his team need to find the form from the back end of last season if they are to remain in the hunt for the long haul this time around.
James Shea was unsurprisingly the busier of the goalkeepers in the opening exchanges and did well to keep out a Mata strike as the visitors saw plenty of the ball.
Luton enjoyed a couple of forays forward and Danny Hylton should have done better when picked out in the box by former United youngster Ryan Tunnicliffe.
The lack of incisiveness from his side would have been a worry to Solskjaer, who had highlighted a late start to pre-season training as a key reason in their weekend loss to Palace.
But, just as Luton appeared set to have seen out the first half without incident, they conceded a penalty less than two minutes before the break.
A United attack broke down and Brandon Williams collected the ball, bursting into the box where he was tripped by George Moncur.
Mata stepped up to send Shea the wrong way and give the visitors a half-time lead.
The visitors started to exert a period of pressure as Jesse Lingard saw a shot cleared off the line before Shea once again did well to push clear a Nemanja Matic drive and then keep out Van De Beek with his legs.
Solskjaer clearly felt he needed more to put a spirited Luton to bed and introduced Bruno Fernandes, Greenwood and Rashford from the bench with 12 minutes to go.
Instead, it was Luton who would threaten next, Henderson making his first save of the night to deny Tom Lockyer, who then saw his follow-up effort cleared off the line.
But then the resources available to Solskjaer would prove the difference as Rashford and Greenwood both opened their accounts for the season in the dying stages to seal a result which certainly flattered the visitors.
Elsewhere, David Raya was Brentford's Carabao Cup hero as the Bees knocked out West Brom.
The goalkeeper saved Grady Diangana's penalty in the shoot-out as the visitors progressed 5-4 after drawing 2-2 at The Hawthorns.
Baggies skipper Hal Robson-Kanu struck twice from the spot in the second half either side of a brilliant overhead kick from Emiliano Marcondes.
Marcus Forss - a former Baggies trainee - then scored his own penalty to force a shoot out.
Marcondes hit the post for the visitors in the first half and Conor Gallagher twice went close before the penalty drama.
In victory, the Bees booked a fourth round home tie against either Fulham or Sheffield Wednesday next week.
And Newport added Watford to their long list of recent cup scalps as they reached the fourth round for the first time in their history with a 3-1 win over the Championship outfit.
Watford arrived at Rodney Parade unbeaten in their three outings this season, but conceded twice in the opening 30 minutes against the League Two outfit, with Carlow's Pádraig Amond adding the third in the second half.
Having knocked out another Championship club - Swansea - in the opening round, their reward is another home tie next week against the winner of tonight's clash between Morecambe and Newcastle.