Southampton boss Ralph Hasenhuttl to BBC Sport: "I think we conceded a stupid goal shortly before half-time. Then we had a big chance for 2-1.
"On the counter-attack it's 1-2. From that our heads are going down and a team with this quality kills you immediately.
"Playing offside all the time doesn't work because of the rule that the linesman has to keep the flag down. It doesn't make sense to do it like this.
"It didn't feel like we were five goals worse than they are."
Spurs manager Jose Mourinho to BBC Sport: "We didn't start bad at all. In the first 10 or 15 minutes we were good. After that we lost control.
"In the centre of our defensive area, we were a bit sloppy. We lost some duels. They got the ball behind us too easy. I was on the bench and thinking I would be happy to get in at 1-0.
"The goal gave us a different position in the game. In the second half, Harry Kane killed the game, the way he connected the game, the way he was dropping, he allowed Son Heung-min into attacking spaces. His performance was amazing.
"In the second half we were too good for them."