Saints once again won away to hit the 40 point mark for the first time in three years as Ralph Hasenhuttl rung the changes and freshened up things which ended in a comprehensive win.
The first shock of the day was that Pierre Emile Hojbjerg was not in the squad, an ankle injury being given as the reason and he was replaced by Oriol Romeu, but that was not the only change Shane Long came in for Obafemi, Will Smallbone for Stuart Armstrong and Jannik Vestergaard for Jack Stephens.
Saints looked a different side in terms of both confidence and attitude and the only time they really threatened was in a 10 minute spell after the break, but by then Saints were well in control and handled things well.
It took only 16 minutes to take the lead when Danny Ings took Will Smallbone's pass and ran across the edge of the box before firing the ball low and hard into the bottom corner, from then on Saints looked well in control with Oriol Romeu looking strong and James Ward Prowse leading by example, Danny Ings was at the heart of everything going forward.
Saints survived Watford's early bluster in the second half and then doubled their leas with 20 minutes to go, Danny Ings cutting out a throw out from the keeper 40 yards out, bursting forward and firing home on 70 minutes.
But the home side pulled a goal back out of nothing on 79 minutes when Jan Bednarek turned in a cross, in truth he had to try and block and he could not be blamed.
But if both sets of supporters thought this might change the game they were wrong, James Ward Prowse firing in a great free kick 3 minutes later to leave the keeper stranded.
The lead could have been extended with Nathan Redmond hitting a post and Che Adams coming close to opening his account in an impressive 15 minute late cameo, he did everything right winning the ball surging forward and hit his shot low and hard, it seemed to have beaten Foster but his the underside of his body and squirmed wide. Adams will be a Premier League player, in 15 minutes he did more than Obafemi in two games, he just needs a goal.
As the commentator on Sky said every Saints player was at least 8/10, but Danny Ings was a different class
It was a good performance with everyone doing their job, indeed Bednarek's OG was the only effort Watford had on target not managing one of their own.
As I said in the preview some games we will get away with it and some we won't, this was one with few errors in, but ultimately it leaves us thinking what if, we could easily have been n the top 10 if it wasn't for the continual errors.
I am not sure whether Pierre Emile Hojbjeg has an injury, but Ralph Hasenhuttl has not been afraid to tweak things, Romeu's performance was better than anything the Dane has put in of late, perhaps by selling Hojbjerg and keeping Romeu we might bring in some cash and replace Hojbjerg from within.