The Black Cats travel south with a 2-1 lead to protect from Saturday's opener at the Stadium of Light, where a certain Manchester United loanee continued to be a shining light for Tony Mowbray's men.
Match preview
A fast start from Luton at the Stadium of Light was rewarded when Elijah Adebayo lashed home an 11th-minute opener following an almighty goalmouth scramble, but as Sunderland began to come forward in droves, the tide soon turned in the Black Cats' favour.
With 39 minutes on the clock, Ethan Horvath was left powerless to prevent Amad Diallo's sumptuous free kick from sailing into the back of the net, before Trai Hume powered a header home from Jack Clarke's cross to send the home crowd into delirium.
Unsurprisingly cutting a bullish figure after the game - insisting that the two-legged semi-final had only reached half time - Hatters boss Rob Edwards welcomes a return to the Kenilworth Road turf in the wake of his side's 14-game unbeaten run coming to an end, with that end-of-season hot streak allowing Luton to nab the third and final podium place in the Championship table.
The hosts' territory was not a happy hunting ground for many visiting outfits during the regular season, with Luton losing just four of their 23 home games and winning five of their last six - the one aberration being a goalless draw with Hull City last Monday.
Since the turn of the year, only West Bromwich Albion and Premier League-bound Burnley have got the better of Luton at Kenilworth Road, where Edwards's men have shipped just two goals in their last six affairs, but Sunderland are well-versed when it comes to away-day resilience.
Also stringing together their own unbeaten run to sneak into the sixth and final playoff position - avoiding defeat in each of their final nine regular-season matches in the Championship - Sunderland are just 90 minutes away from seemingly unthinkable back-to-back promotions.
The Black Cats, who have not competed in the top tier of English football since the 2016-17 campaign, were likened to "snarling dogs" by an overjoyed Mowbray on Saturday, as Luton felt the full force of their hosts' bite in front of a boisterous Tyne and Wear crowd.
Saturday's first leg marked the eighth game in a row in which Sunderland have found the back of the net, and while one clean sheet in six is not the most reassuring statistic, their exploits on the road make for positive reading for those in red and white.
Indeed, Mowbray's side ended the regular season with three away victories on the trot - conceding just one goal in their last 450 minutes of football on rival territory - and a total of 39 points on the road could only be bettered by Burnley, Sheffield United and, of course, Luton.
Prior to Saturday's showdown, Luton and Sunderland had remarkably played out four successive 1-1 draws - also doing so in the 2018-19 League One season. The meteoric rise of both clubs since those days in the third-tier doldrums has been admirable, but only one can vie for Premier League football against either Coventry City or Middlesbrough at Wembley on May 27.
Luton Town Championship form:
W
D
W
D
D
L
Sunderland Championship form:
W
D
W
D
W
W
Team News
Luton very nearly came through Saturday's defeat unscathed, but Alfie Doughty was forced off with cramp with just a few minutes to go, and his condition will need to be closely monitored in the coming days.
Reece Burke and Daniel Potts will be on standby if Doughty is not given the green light to line up here - which could see Amari'i Bell shift to the left-hand side - but the hosts should otherwise be working with a full complement of troops and should see little reason to make many adjustments.
Similarly, Sunderland also exited the first leg with not one but two fresh concerns, as Patrick Roberts and Alex Pritchard were both forcibly withdrawn in the dying embers of the match.
Mowbray is confident that Pritchard's knock will settle down in time for the second leg, but he admitted more concern over Roberts's apparent thigh problem as he continues to work around a plethora of long-term absentees.
Elliot Embleton (ankle), Danny Batth (knee), Ross Stewart (Achilles), Corry Evans (ACL), Aji Alese (thigh) and Dan Ballard (hamstring) make up a sextuplet of known absentees for Sunderland, and while Niall Huggins would be a like-for-like replacement for Roberts at right-back, Mowbray is reluctant to throw the 22-year-old in from the first whistle given his limited playing time - he may have little choice here, though.
Luton Town possible starting lineup:
Horvath; Bell, Lockyer, Osho; Drameh, Mpanzu, Nakamba, Clark, Doughty; Adebayo, Morris
Sunderland possible starting lineup:
Patterson; Huggins, O'Nien, Hume, Gooch; Neil, Ekwah; Diallo, Pritchard, Clarke; Gelhardt
We say: Luton Town 1-1 Sunderland (Sunderland win 3-2 on aggregate)
Even when a spate of serious injuries have threatened to derail their promotion charge, Sunderland have overcome adversity time and time again, thanks in no small part to their well-documented staunch defence on the road.