Luton Town have recorded a shock 3-1 win over Bristol City in their League Cup first-round clash at Kenilworth Road, Jack Marriott weighing in with a memorable brace.

The visitors were quickest off the starting blocks as Luke Ayling crossed into the middle four minutes in, Steve McNulty's attempted clearance sending the ball cannoning off the top of the bar.

Luton continued to struggle throughout the early stages of the first half as Derrick Williams, Callum Robinson and Ryan Fredericks all enjoyed chances before the quarter-hour mark.

Fredericks was next to threaten as he galloped down the touchline again and searched for Aaron Wilbraham in the box, but Luke Wilkinson managed to thwart a likely tap-in with a timely block.

The hosts would have to wait until the 30-minute mark before registering their first chance on goal, Marriott gathering Dan Potts's flick and firing straight at Ben Hamer.

Nevertheless, the League Two side had the last laugh in the first half as Marriott marauded down the left, cut inside onto his right and hit a low shot in off the post.

The second half turned into a nightmare for the Robins as Pelli Ruddock Mpanzu's incisive through-ball just before the hour fell to Paul Benson, who duly struck low past Hamer to double the Hatters' lead.

Four minutes later Marriott weighed in with his second of the game and his side's third, collecting Stephen O'Donnell's pass before bearing down on goal and firing home to put the opposition out of reach.

City rallied round and pulled a goal back in the 71st minute through Robinson, who collected Luke Freeman's through-ball, took a touch and curled a shot past Tyler at his near post.

This would be the limit of their fightback, however, as their opponents held firm and rode their luck to ultimately see the game out and secure passage to the second round of the competition.