Luton finished the Championship season 11 points ahead of Sunderland, but it will be their task to play catch-up in their play-off semi-final after they suffered a 2-1 defeat at the Stadium of Light on Saturday.
Both sides might look back at the first leg with feelings of regret.
Luton failed to build on Elijah Adebayo's 11th-minute goal, but the Black Cats might feel they could have built a bigger lead after a dominant second-half performance.
The upshot is a finely balanced tie with everything to play for.
Play-off games are not always the greatest of spectacles, but Sunderland and Luton served up an exciting first leg and there should be more of the same in Bedfordshire.
Luton will have to take the game to the visitors and will probably adopt a higher press in an effort to disrupt the Black Cats' passing rhythm.
That should enable them to win the ball in good areas and allow them to feed a lot more balls into the box for physical forwards Carlton Morris and Elijah Adebayo, who thrive on service from wide areas.
Sunderland's injury-hit defence will be put under greater pressure and is likely to buckle at some stage.
But there are risks attached to a more front-foot strategy from Luton, because it will create space in behind for Sunderland to exploit.
Sunderland have got some fast, skilful forward players and two of their key men, Amad Diallo and Jack Clarke, came to the fore with a goal and an assist in the first leg.
Both will pose a major threat to Luton and it seems likely that Sunderland will find the net for a ninth successive game.
Luton's 20-goal top scorer, Morris, was kept fairly quiet in the first leg, but he could be far more involved at Kenilworth Road and looks well worth an interest to net the opener.
Morris bagged the first goal in Luton's 1-1 draw at home to Sunderland back in October and he approached the play-offs with plenty of confidence, having scored four times in his last five league appearances.
Adebayo was Luton's goalscorer on Wearside, but he notched just seven league goals this season and looks of lesser interest at .
Morris has 20 goals to his name in total this season and, as well as four in his last six appearances, he also netted five in seven games before a mini-drought of three without a goal following that.
That means in total he has nine goals in his last 16 outings and, of those, no fewer than six have been the opening strikes in their respective matches.
That stat is enough to suggest that Morris could be a more than decent option at 5/1 to open the scoring on Tuesday evening.
It could turn into a long night in the second leg, but the hardest part of the tie for Luton was always going to be their trip to the north east.
Tony Mowbray's team had a 59 per cent share of possession on home turf, which helped them to prevent the Hatters from sustaining their attacks.
However, it will be far more difficult for them to take control of the second leg at Kenilworth Road.
Luton had triumphed in five home games in a row before a disjointed 0-0 draw against Hull City on the final day of the season when they were more focused on resting players than securing maximum points.
They will fancy their chances of getting back to winning ways and should at least take the tie to extra-time.
With just one goal separating the two teams following the first leg, the return is set up to be another tense tussle.
No away goals counting double also plays into the hands of those who think this tie will extend beyond normal time on Tuesday evening, with a one-goal win in Town's favour meaning there will be an additional 30 minutes left to find a winner.
However, given the way that both sides approach the game, it seems unlikely that either will sit back in extra-time and settle for taking their chance in a potential penalty shootout.
With that in mind, seeing the tie settled in extra-time offers some appeal at .