Spurs were drawing 1-1 when Son stepped up to the penalty spot at the end of the first half. And, although his initial spot-kick was saved by Pepe Reina, the South Korean reacted quickly to follow up and score.
In doing so he became the first Asian player to hit 50 goals in the Premier League and he took his tally to 51 later in the match.
Watch Son score twice at Villa
"I've scored 50 Premier League goals but without the team, without the supporters, it's impossible," Son told Spurs' official website.
"I just want to share this feeling with the fans, everyone in South Korea and with the lads. I just want to say thank you for helping me."
Highest-scoring Asian players
|Son Heung-min||51||South Korea|
|Park Ji-sung||19||South Korea|
|Ki Sung-yueng||15||South Korea|
|Lee Chung-yong||8||South Korea|
Son's second goal at Villa Park was also significant, again not only for Spurs' top-four challenge but their history books too.
Coming after 93 minutes and 34 seconds, it was the club's latest winning goal in the Premier League for over a decade.
"It's really amazing," said Son. "Winning is always positive but especially that way, how we won - 2-2, last seconds - a better afternoon is impossible."
Spurs' latest PL winners*
Alexis Sanchez holds the record for the latest Premier League winner since Opta began collecting such data in 2006/07.