The Hatters have won two games from two and are third in the table on goal difference, two points better off than opponents Watford after a mixed start for Vladimir Ivic.
Luton may have fallen to a 3-0 loss to Manchester United in round three of the EFL Cup on Tuesday, but Nathan Jones will be delighted with his side's start to the season.
After claiming a 1-0 win away at Barnsley on the opening day, Town followed that up with a last-gasp 2-1 victory over Derby County last time out.
Luton have very much picked up from where they left off flast season when dodging relegation by three points, with Jones leading the club to 22 points from 11 games.
To put that into some context, only Brentford (24 points) have fared better than the Hatters since Jones returned in June.
This is certainly not a gimme for Watford, then, especially on the back of their 3-1 EFL Cup loss to League Two opposition Newport County in midweek.
The Hornets' first season in the second tier since 2015 has started well enough, following up a narrow 1-0 win over Middlesbrough with a stalemate at Sheffield Wednesday.
Watford are now looking to keep a clean sheet in their first three league games of a season for the first time since 1988-89.
That was five seasons before the Hatters' most recent victory in this fixture, having gone nine league games without a win against Watford.
However, this will be the first league meeting between Watford and Luton since April 2006, with that one ending in a 1-1 draw at Vicarage Road.
Watford Championship form: WD
Watford form (all competitions): WWDL
Luton Town Championship form: WW
Luton Town form (all competitions): WWWWL
Tom Lockyer made his first start for the club after joining from Charlton Athletic and Clark started after netting the winner versus Derby last week.
Jones therefore has a couple of big selection calls to make, but he will likely revert back to something close to the XI that started last weekend.
Watford possible starting lineup:
Foster; Ngakia, Cathcart, Kabasele, Wilmot, Sema; Quina, Cleverley, Chalobah, Pedro; Murray
Luton Town possible starting lineup:
Sluga; Cranie, Pearson, Bradley, Norrington-Davies; Berry, Ruddock, Rae; Cornick, Collins, Lee
We say: Watford 2-0 Luton Town
Luton may have collected more points than Watford in their opening two fixtures, but the Hornets boast one of the finest squads in the division - even more so now that Sarr and Deeney are back - and should have enough quality to end their opponents' winning start.