Ralph Hasenhuttl has proved over the past week that he possesses one of the key traits of a top manager.

Football bosses are no different to the rest of us in our working lives. They make mistakes.

In theory, to get to Premier League level you have had enough experience that some of the more fundamental errors should already be out of your system.

But that doesn’t mean top level managers are immune from slip-ups, from believing something is correct even when it appears it isn’t.

It is unrealistic and unfair to expect these guys to be perfect in their decision making no matter how high profile they or their club are or how much they are earning.

What is key is that they are prepared to learn from their mistakes and don’t let ego or stubbornness get in the way.

Not many of them normally admit they made an error, but when you see it quickly rectified then you know it has been acknowledged on some level.

Hasenhuttl has demonstrated this in the past seven days.

Having experimented with his defence for several weeks and largely got away with it – which is in itself a justification for arguing it wasn’t a mistake at all – it came unstuck against Bournemouth.

It was pushing the luck just one time too many.

The defence was a mess, the first half tinkering didn’t make things better and unlike in other recent matches the Cherries were in no mood to be generous opponents and took full advantage to score the goals that took the game beyond Saints before Hasenhuttl made the correct changes at half time.

Maybe that was a blessing in disguise, because Hasenhuttl obviously decided he couldn’t experiment again in the derby match at Portsmouth.

And, so, common sense prevailed and Hasenhuttl picked an absolutely spot-on team.

He went simple with the formation so in the white heat of the Fratton Park atmosphere the players would not have to overthink what they were meant to be doing.

He recalled Ryan Bertrand. No matter what, if anything, has gone on between the two there is no doubt that Bertrand is the best left sided defender at the club and is sorely missed when he’s not playing, and he now knows that for sure.

He packed the team with experience, bringing in the likes of Alex McCarthy, Maya Yoshida and Danny Ings to ensure a solid side who wouldn’t be intimidated.

Would he have done all that had he have got away with it again against Bournemouth?

Of course, it’s impossible to be certain, but what we can say for sure is that the side he selected for the Pompey tie was correct.

And so it appears it was lesson learned and mistake corrected, and all before a game which had it have gone wrong could have destroyed his Saints legacy unless he produced something truly outstanding during the rest of his stint at St Mary’s.

What a night it was for Saints.

It’s fair to say that they should have won. They are two divisions above Portsmouth and the quality of their squad is far superior, but in football that is no guarantee.

A lot of the little levellers that Pompey would have needed showed up such as the driving rain and strong wind, which whipped up before kick-off and Saints had to defend in the first half.

Pompey started well and really should have taken what would have been a deserved lead in the game, but when they didn’t even their players seemed to know the writing was on the wall.

Sure enough, Saints’ class told and the one-sided final score gave an added sheen to the result.

The atmosphere at Fratton Park was intense. Being an evening game and under the lights just turned it up another notch.

Thankfully the police did well and there was minimal trouble outside the ground, which meant the football was the star of the show.

The wall of noise at Pompey’s old ground made it a true derby and showcased the intensity of this fixture to the world with so many other football fans seemingly keen to shrug it off in the build-up.

Hasenhuttl said before the match that he understood what this game was all about. When pressed on the topic it felt like he didn’t. He dismissed it in a fashion by saying he and his players had played in other derby matches so it wasn’t a new experience.

He understands now and the outpouring from the Saints fans towards him and the team after the victory and the legacy he has now secured means that despite one sorry defeat against a competitive rival and one win against a team two divisions below it has been a huge week for Hasenhuttl.