Saints’ first top-flight outing since last week’s takeover by investment firm Sport Republic was an emphatic affair thanks to goals from Jan Bednarek Armando Broja and Che Adams, plus an own-goal from Bees goalkeeper Alvaro Fernandez.
A memorable display – watched from the stands by lead investor Dragan Solak – was even more impressive given the hosts were taken to extra-time in Saturday’s gruelling FA Cup win at Swansea and lined up in an unfamiliar 3-5-2 wing-back system due to the absence of a recognised right-back.
“I think they (the owners) saw a good game from our side,” said Hasehuttl. “It was a very impressive performance.
“It’s for him (the owner) important to see that there is a team on the pitch who you can identify with and the way we want to play football is something everybody enjoys here for a long time now.
“It was absolutely fantastic after a tough Saturday.
“From the first moment on, I must say that I am very proud of my team, we played a different shape, they did it fantastic, the second half even better.
“You could feel it in the last weeks that we are getting more and more flexible and young players are getting better and better, everybody is making better steps forward.
“In this tough league to win the games is always super difficult but I’m super happy with my team in the moment, the way we progress and develop our game is fantastic to watch.
“This is also for a new owner a good sign that we have here a team that is really working well.”
Victory for Southampton moved them to 11th in the table, a point and two places above their opponents.
In-form defender Bednarek headed the home side ahead inside five minutes with his third goal in five Premier League outings before Brentford midfielder Vitaly Janelt briefly levelled proceedings with a fine volley.
But the evening belonged to Hasenhuttl’s rampant hosts and, after the unfortunate Fernandez inadvertently restored Saints’ lead before the break, Broja and substitute Adams added gloss to a notable evening.
The resounding win was the first time Southampton had scored more than three league goals in a game since a 4-1 success over Everton in November 2017 – more than a year before Hasenhuttl’s appointment.
Bees boss Thomas Frank was unhappy with his side’s display and rued the timing of Broja’s breakaway strike early in the second period.
“Fair play to Southampton, they did their job, but my job is to look at our performance and that was definitely not good enough today,” he said.
“We know that we need to be playing every second of a Premier League match 100 per cent, we definitely didn’t do that today in terms of focus, winning the duels.
“The timing of the third goal is killing us and then it’s game over.”