It wasn’t the most fluid display from Solskjaer’s side but Juan Mata opened the scoring from the spot after Brandon Williams was felled in the Luton penalty area just before half-time.
Both side had opportunities in the second half but Marcus Rashford scored three minutes before the end of normal time after latching on to a smart layoff from Mason Greenwood to all but wrap things up.
Greenwood, who had only been on the pitch for five minutes, then slotted home in added time with a cool left-footed finish.
At the other end of the pitch, It was a solid night’s work from Henderson, who will battle David de Gea for the No. 1 spot this season following a season on loan at Sheffield United, and he made an impressive save prior to United’s two late goals to keep his side in front.
Making his debut, he kept a clean sheet and Solskjaer was pleased with his performance between the sticks as United bounced back from a 3-1 defeat to Crystal Palace in their Premier League opener at the weekend.
‘Some positives of course,’ Solskjaer said after the match. ‘We’ve got a keeper back there who does his job.
‘We scored some nice goals towards the end, when you can see the impact they [Bruno, Rashford & Greenwood] had. Apart from that, a good workout.’
On Henderson’s late save, he added: ‘That is probably the job our keepers sometimes have to do, you have to make saves when needed and David [de Gea] has done that for years and Dean did that today.’
‘He did a great save and somebody also cleared the ball on the line. I think we did OK.
‘We have all not been training together for too long and now it is important to get the rhythm back and to get confidence. The confidence comes with results.
Henderson was clearly delighted to make his debut.
He posted on Instagram after the match: ‘I dreamt about this my whole life!!
‘Unbelievable feeling to make my debut for the club I love!! Clean sheet and a win to top it off!!!’