Story of the match
Despite both teams brimming with confidence after their respective 3-0 victories on Saturday, neither side were able to create anything of note in the early exchanges.
The first opportunity of the half fell to Luton Town centre-back Sonny Bradley, but his scuffed effort fell harmlessly wide of the target.
The visitors enjoyed long spells of possession, but struggled to get behind a well-organised Middlesbrough defence.
The hosts grew into the game as the half wore on with Marvin Johnson and Marcus Tavernier providing an outlet for Boro's more central players.
Middlesbrough's best chance of the first 45 came in the 42nd minute when Dael Fry fired over from the penalty spot after The Hatters had failed to clear a free-kick.
The hosts started the second half brightly and nearly took the lead in the 47th minute when George Saville's effort sailed just over the bar.
Chuba Akpom opened the scoring for Boro in the 52nd minute, tapping home Marvin Johnson's driven cross, after the winger was awarded too much space on the left-side of the box.
Despite their positive start to the half, Middlesbrough found themselves a man down and with a penalty to face in the 67th minute in a real passage of madness. Sam Morsy was the man who received the red card after he had supposedly stopped the ball from going in with his hand.
James Collins stepped up to take the resulting penalty and found the back of the next, but after consulting with his assistant, the pair adjudged that Collins had two touches of the ball before it had hit the net.
Luton still struggled to make any chances after the visitors were reduced to ten men, but their best opportunity came in the fourth minute of stoppage time, when Luke Berry's headed George Moncur's corner straight into the arms of Bettinelli.
It was a game of few chances and Middlesbrough took the only real opportunity of the game. Both sides found it difficult to break each other down in the first half and were unable to create anything. Boro started the second half off a lot better, grabbing their goal before defending their lead successfully.
Luton were unable to capitalise on the big opportunity that was presented to them in the 67th minute and ultimately failed to make any chances in the half an hour they had the man advantage. The Hatters have now gone four away games without scoring.
For the hosts, Marvin Johnson particularly stood out, giving the makeshift full-back Matty Pearson a tough time. He got around the back of the Luton defender on a number of occasions and provided the assist for the eventual winner.
Luton enjoyed a lot of possession, but did not threaten in the final third. Defender Tom Lockyer won the majority of aerial duels and travelled forward with the ball well, starting a number of attacks for The Hatters.