The South Korean became the first player to score a competitive goal at the Tottenham Hotspur Stadium as Spurs celebrated moving home by beating Crystal Palace 2-0 in a housewarming party to remember.
He takes his place in the record books alongside Tom Smith, who scored the first goal at White Hart Lane way back in 1899.
Asked if the goal, which was heavily deflected and eased the tension after a nervy opening 55 minutes, was the best moment of his Spurs career, he said: "Yes, probably. Every single moment at Tottenham is special.
"It means a lot, especially tonight I am very proud of my team-mates, proud of this stadium, proud of the fans. Everything is positive at the moment. I am really the happiest guy in the world.
"It is amazing, to play in this amazing stadium and give me this opportunity, it is unbelievable. It was a great result, that is the most important thing."
Spurs were away for 689 days and had to play at Wembley 51 times while White Hart Lane was demolished and their majestic 62,062-seater stadium was built.
The win over Palace, which was secured by Christian Eriksen's late goal, was only the second time Spurs' players have been to the stadium but Son says it already feels like home.
"It sounded very loud," he said. "Wembley is one of the most beautiful stadiums in the world but it was not actually our home.
"We finally felt like we came back home, on the pitch, but also in the stands as well, it was so loud, it gave us a boost for this moment."
Tottenham's return to their own home could not have come at a better time as their league form was floundering, with one point from five matches seeing their top-four aspirations come under serious threat.
But for them to be in the race for the top four this season is an impressive achievement, given the distractions of the new stadium, which suffered an eight-month delay.
Striker Harry Kane says the club no longer have any excuses and have to get the job done in the last few weeks of the season.
"Being on the pitch just felt like home," Kane said. "In the final year at the old White Hart Lane we finished unbeaten and I hope this will be the same.
"Obviously we have got four games left to look forward to and hopefully we will get the results.
"It has been a tough few weeks for us and we are in a battle for the top four. Obviously with (Manchester) United losing, it was up to us to gain a few points on them.
"We have got four more games here at home and, yeah, we want to win them. We are confident anyway. We feel like we have done well this season obviously with everything that has been going on.
"There are no excuses now. We are here, we are home, and if we play like that we will be all right."
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies