Southampton captain James Ward-Prowse was left frustrated after their 4-1 defeat at Tottenham.
Despite the captain's early goal putting them in front, Saints fell to a oss in north London, as they were soundly beaten by Antonio Conte's side.
"Of course, it's a disappointing start," said the Southampton skipper. "I think we did well to get through that initial early period. We knew there would be a lot of pressure and a lot of energy from them.
"Playing against a Champions League team, we know the level they're capable of playing and we took a lot of confidence into the game obviously having performed well here last year, but of course a disappointing end to the game and when we don't play well for the whole 90 minutes of the game these teams punish you and they did that today.
"The message at half-time was to stay in the game. We knew they were only a goal ahead and the next goal was key in the game to be honest. We didn't start the second half very well with the goal being disallowed for offside and that was kind of a wake-up call for us.
"But, like I said, when we're not at it 100 per cent for the whole duration of the game, these players and these teams will punish us and we certainly felt that today."