"In the last three games, we've been able to win two games against sides beside us at this moment," he said, referring to the 3-0 defeat of Reading and this victory.
"It has been a tough old season right from the start and I just feel that win today, obviously before Christmas and with the programme we have coming up in the next three games, is massive for us.
"We got a bit of confidence from that, although we have a fair few games to go. The game was very tight as I expected it to be. Southampton are in really good form, particularly here, and they are on a good run at the moment.
"It is hard to say but I think we got a bit of confidence from the second-half performance at Old Trafford [last weekend despite losing 3-1 to Manchester United].
"I thought we took it into the game and started brilliantly, with Stephane Sessegnon having a great shot and the goalkeeper making a great save.
"Then the game started to develop into a bit of a pattern, with attacks by Southampton and a couple of counter-attacks by ourselves, so it was important to get the first goal.
"We got it at a great time in the game and then dealt with a second-half onslaught, which was expected.
"Southampton tried to break us down and put a few balls into the box, but I thought we dealt with them pretty okay."