When Aidy Boothroyd took his fledgling side to the Potteries in April 2005 they needed a win to stave off the threat of relegation. Stoke duly obliged and Heidar Helguson ensured another season of Championship football.
It was then the Staffordshire side who beat off Watford's challenge for automatic promotion in 2008, clinching promotion to the Premier League as runners-up and staying there ever since.
And when Watford made the trip to the Bet365 Stadium in January of last season, it was seen as a must-win for Walter Mazzarri.
So much so that the unpopular Italian crowbarred a half-fit Valon Behrami into his starting XI in a desperate attempt to halt a run of five defeats in seven. Stoke won 2-0 and it soon became six.
And Saturday's meeting at Vicarage Road – while unlikely to feature high in Match of the Day's running order – is every bit as important. Last season Watford were beaten home and away by Mark Hughes' side. But the Potters finished 13th, breaking the monotony of three consecutive ninth-place finishes with a season of regression.
For so long held up as the shining beacon which newly-promoted clubs should emulate, Stoke have gone stale. Capable, on their increasingly infrequent day, of turning in a result, more often than not they are boring. Plain and simple.
They're unlikely to get relegated under Hughes and they're even less likely to crack a European place either. So what are they playing for? The odd 1-0 win over Arsenal – satisfying though it may be given the peculiar rivalry between the two clubs – is not enough to quench supporters' thirst during the long droughts between.
It's why Watford are so desperate to avoid being sucked into that pattern. When the Hornets announced Mazzarri would be leaving at the end of last season supporters breathed an audible sigh of relief.
The Italian was the embodiment of settling for mediocrity. Externally, however, the club was chastised for seeing off a second manager in successive seasons despite achieving the minimum aim of staying up.
The emphasis, there, being on the word minimum. Since the Pozzo family took over in 2012, Watford has been transformed as a club. Everything about it has been brought kicking and screaming into the 21st century. And they're not done, not by a long shot.
Simply existing as a Premier League club, picking up your hundred-odd million each season and going again isn't enough. The rewards for being in Europe, both in prize money and being able to attract and then sell players for vast sums, are far greater
Speaking on BBC 5Live at the time of Mazzarri's departure, chairman Scott Duxbury said: “I don’t think we’re different in the sense that we simply have aspiration and ambition. I think there’s been certain pundits recently who said we should be happy just surviving; with the crumbs from the Premier League table. I’m sorry, but we want more than just to survive. We want to be a club that is progressive.”
The man who replaced Mazzarri, Marco Silva, has rightly earned many of the plaudits this season. Without making wholesale changes to the personnel, the Portuguese coach has transformed the Hornets from one of the least inspiring sides in the Premier League to genuine top-half contenders.
A 6-0 shellacking at the hands of the other-earthly Manchester City aside, Watford have enjoyed a superb start to the season. An 3-3 opening-day draw against Liverpool set the tone while victory over Arsenal and a creditable, late, 4-2 loss at champions Chelsea suggest Watford will go toe-to-toe with the best the Premier League can offer.
More important – in terms of the bigger picture – would be a resounding win over Stoke on Saturday. That will suggest Watford have left the Potters, and teams of their ilk, behind and are moving onto bigger and better things.
That is the sign of real progress. The top six have to drop points occasionally. But beating established sides like Stoke, West Brom or Crystal Palace with relative ease is what more ambitious sides do. And Watford are certainly that.