Saints got points on the board at their third attempt, but it was a tough task that saw Saints have to dig in and earn the win right up to the final whistle.
Brighton had made a solid start to their Premier League campaign and they clearly where in no mood to make it easy for Saints.
The first half an hour saw both sides evenly matched and it was hard to predict a winner at this stage.
The game changing moment came in the 30th minute when Andone was given a straight red for a foul on Valery, fair play to former Saint Graham Potter now Brighton manager for calling it how it was and not moaning about it.
His side had to play an hour with 10 men, but they did not look like it, they worked harder to make up for their deficit in numbers and this was not an easy game for Saints to win.
They had the ball in the Saints net in the 39th minute, but it was ruled out by VAR, the worrying thing though was this looked the clearest offside and indeed impediment of the goalkeeper that you will ever see, yet it had to go to VAR, the problem now seems to be the officials are scared to make a mistake so they are relying on VAR to make the decision for them.
The longer the game went on the more Saints looked like winning it though, Hasenhuttl had kept his side focused making sure they didn't charge forward in numbers and pay the price at the back and just after half time he made the change that won the game bringing on Moussa Djenepo who within two minutes had scored a superb goal worthy of winning any game.
Having gained the lead Saints still had to hang on to it though and that meant some tough defending at Brighton refused to lay down and die, in the main Saints did it well, but in the final minute with the score still 1-0 they really should have seen the home side equalise, the old problem of leaving a man unmarked at the far post, luckily the shot hit that post rather than the net, but it really was a chance wasted for the Seagulls.
They paid heavily for that miss as Saints then scored at the other end to put the game out of reach, Soifiane Boufal ending a mazy run with a low cross that Nathan Redmond poked across the line to cap a fine performance with a goal.
This was a decent performance from Saints, but they can and have to play better, we failed to put the game to bed and then nearly handed them the draw on a plate, of course sometimes you can't stop goal attempts, but we hand our opponents far too many.
Overall though it was a good team performance and hopefully gives us the confidence to kick on and push ourselves up the table, arguably we have as tough an opening four games as anybody, so to get a win from them is good, we now have to build on this.
It was also pleasing to see us adapt to a situation, this one being the absence of Ryan Bertrand, meaning a reshuffle at the back with Valery switching to the right and Kevin Danso coming in for Yoshida.
But the most important thing was that we got the three points on the board and the season is now underway.