The Hornets beat bottom side Norwich City in midweek and are four points above the drop, while Newcastle - thrashed 5-0 by Manchester City - are jostling for position in mid-table.
Nigel Pearson praised the "strength" of his Watford side to dig deep against doomed Norwich and pick up all three points in a vital 2-1 win at Vicarage Road.
That win, which came courtesy of Danny Welbeck's spectacular overhead kick, ended the Hornets' six-game wait for a victory in the Premier League.
After beating Liverpool 3-0 at the end of February to claim one of the shock results of this or any other top-flight campaign, Watford accrued one point from the next 15 available.
It was a run that left Pearson's men at serious risk of dropping into the Championship, but the win over Norwich gives them a healthy four-point buffer on the two sides below them.
However, Aston Villa and Bournemouth do still have a game in hand to play on Thursday, against Manchester United and Tottenham Hotspur respectively.
Watford still have work to do if they are to stay afloat, and with Manchester City and Arsenal to face in their last two games they could do with a victory on Saturday.
There is perhaps no kinder fixture for Watford than the visit of Newcastle, either, with United stuck in mid-table and possibly already thinking of their shortened summer break.
Steve Bruce's men won three games in a row either side of the coronavirus-enforced hiatus to ensure that relegation would not be a concern for them this season.
Results since then have been largely mixed, with a 4-1 away win at Bournemouth coming a week before a 5-0 thrashing at the hands of Man City, summing up their inconsistent nature.
United were truly dreadful at the Etihad Stadium and could have lost by even more in the end, with the Magpies struggling to adapt to a five-at-the-back system.
Still, there can be no excuse for the type of display produced by the Toon and they have to quickly pick themselves up for this trip to Hertfordshire.
Watford's Premier League form: LDLLLW
Newcastle United's Premier League form: WWDWDL
Newcastle United's form (all competitions): WDLWDL
However, Pearson will want to name something close to the XI that started the win over Norwich, which should mean Welbeck retaining his place in attack after his match-winning strike.
Captain Troy Deeney has gone six games since last finding the back of the net but is expected to lead the line once again against for the Hornets.
As for Newcastle, Bruce is sweating on the fitness of the likes of Saint-Maximin, Carroll, Hayden and Lascelles for this trip south.
Nabil Bentaleb was poor against City and is likely to be replaced by Matthew Longstaff in central midfield, while Miguel Almiron is another in line for a recall after being given a breather in midweek.
Watford possible starting lineup:
Foster; Femenia, Kabasele, Dawson, Masina; Capoue, Hughes; Sarr, Doucoure, Welbeck; Deeney
Newcastle United possible starting lineup:
Dubravka; Manquillo, Schar, Fernandez, Rose; Ritchie, Longstaff, Shelvey, Joelinton; Almiron; Gayle
We say: Watford 1-0 Newcastle United
This is the easiest of Watford's remaining fixtures and they could really do with picking up another victory. Newcastle will not be as bad as they were on Wednesday, and Bruce will have more players to choose from, but we can see the hosts grinding out a precious win.