Ralph Hasenhuttl will never forget beating Portsmouth after Southampton ended their 35-year wait for a derby win at Fratton Park in style.

Hostilities were renewed for the first time since 2012 at a rocking Fratton Park, where the League One strugglers' determination to cause an upset was clear during a bright start to the Carabao Cup third-round clash.

But Southampton's players rallied rather than wilted and Danny Ings scored a quickfire double to put his hometown club on course for a victory wrapped up in style be Cedric Soares and substitute Nathan Redmond.

The 4-0 triumph was Saints' first win at Pompey since 1984 and Hasenhuttl loved his first taste of the south coast derby.

"We will not forget this evening – and the fans too," the manager said.

"It was a fantastic atmosphere until the end and to score four goals here is fantastic.

"It is more than only reaching the next round. It is about reaching the hearts of the fans.

"I am very happy for them.

"I knew it was massive game for them and I think we really didn't start well in this game, but the players knew they had to fight for every inch and after the 1-0 it was a much better game for our side.

"After the 2-0 I was not sure if this game is done for us so you never know if they make the 1-2, then suddenly everything is alive again and it gets difficult for you.

"At 3-0 you know it is done. It was a hard job to do but the guys did it well."

Hampshire's largest ever football policing operation was in place for the clash of these old foes and Hasenhuttl was blown away by the derby atmosphere, saying "I have never had such an atmosphere in a stadium so far".

"I was hoping it is coming in a way that you can also celebrate the football and if you see such a game here then you know why football is so popular in England," the Southampton boss added.

"It is exactly what it is. A little bit raining, a fighting game and an unbelievable crowd that never stopped singing.

"If you think about English football, then that for me is English football."

Portsmouth fans cheered their side long after seeing the match decided so comprehensively by their bitter rivals.

The supporters certainly could not fault their players' efforts, nor could under-fire Pompey boss Kenny Jackett.

"We had a lot of pressure, a lot of chances, opportunities, one on ones and set pieces but we didn't take them," he said.

"We went two up front and tried to bring the crowd into play and they were fantastic.

"We did need that first goal, in both halves. The chances and the opportunities we had, the amount of balls into the box, we couldn't quite capitalise on.

"As a manager, I didn't want to come away not having a go tonight, and just shutting up shop.

"We tried to pressure them, ruffle them to a degree and if we had got the first goal, it could have been different."