Heung-min’s stoppage time winner saw Tottenham recover from being a goal down with a minute left against League Two Wycombe before winning 4-3 in an FA Cup fourth round tie.
Paul Hayes, who had earlier headed against the bar, shocked the Premier League side with a sweetly struck left-footed volley to put Wycombe ahead.
The captain grabbed his second from the spot to double the visitors’ lead.
But Son’s deflected effort on the hour and a Vincent Janssen penalty four minutes later pulled Spurs level.
Substitute Garry Thompson headed in Myles Weston’s cross with seven minutes to go to put Gareth Ainsworth’s side back in front.
But a composed 89th-minute finish from Dele Alli pulled Spurs level again, before Son scrambled in a late winner.
Other results saw non-league side Lincoln City reach the last 16 of the FA Cup for the first time in 115 years.
They secured a superb 3-1 victory over Championship leaders Brighton at Sincil Bank.
Premier League sides Chelsea, Manchester City and Arsenal all recorded comfortable wins as they progressed to the fifth round of the FA Cup.
Premier League leaders Chelsea swept aside west London rivals and Championship side Brentford 4-0 at Stamford Bridge, while Man City thrashed Sam Allardyce’s Crystal Palace 3-0 at Selhurst Park.
The last game saw Arsenal claim the biggest scalp of the day, thrashing Premier League opponents Southampton 5-0 away at the St. Mary’s Stadium.
A brace from Danny Welbeck and a hat-trick from Theo Walcott ensured the Gunners progressed to the last 16 of the FA Cup.
The News Agency of Nigeria (NAN) reports that they secured the win with manager Arsene Wenger watching from the stands.(NAN)