"I think it is the best goal in my life," Son, 27, said.
"I don't know what happened until the end! When I got the ball l tried to pass to Dele Alli and waited for his movement.
"But I couldn't find him so I just went and went. I'm happy to score this goal."
"We have given the ball away five times at the start and we can't do that," the Clarets boss said.
"It is unlike us to be so open and to give the ball away in so many bad areas. It was a tough day. We had lots of the ball, couldn't open them up.
"We have proven before we can make these games hard and we have to get back to that."