"Always when you play in this type of competition against a very good side like Dortmund it is hard", said the Argentine.
Tottenham looked unfazed by the absence of injured captain Harry Kane and Dele Alli, scoring all three goals in a strong second half to take control of the tie and leave the Germans on the brink of a European exit.
Son has now scored nine career Champions League goals - among Asian players, only former Uzbekistan striker Maksim Shatskikh managed more, with 11 for Dynamo Kiev.
"We've got to win the second leg before we can even look at how far we can go".More news: One of Jennifer Aniston’s Exes Just Wished Her Happy Birthday On Instagram!
"Next time Son scores I will go to the dressing room, have a shower and wait for the game to finish", he joked to the media".
"Son was fantastic again".
Son converted Spurs' first shot on target at Wembley on Wednesday as the Bundesliga leaders were made to rue a string of first-half misses. "It's good to play against great competition in any league, but I'm definitely looking forward to next season".
"His smile, he translates good energy and his performance every game is improving".
Mauricio Pochettino's side were second best during the opening 45 minutes but were dominant after the interval and took the lead just two minutes after the restart when Heung-Min Son cushioned home an exquisite cross from Jan Vertonghen. It is special playing for Tottenham in the Champions League'.
A late goal from substitute Marco Asensio helped Real Madrid narrowly defeat a determined and young Ajax squad on Wednesday night, as Los Blancos prevailed 2-1 in the first leg of their Champions League Round of 16 match-up at the Amsterdam Arena. A point in Frankfurt is okay and drawing 3-3 after leading 3-0 is also part of the game. I really enjoy watching him.