Mauricio Pochettino’s side took a huge step towards the quarter-finals with a superb second half performance in which they put the Bundesliga leaders to the sword, with a goal from Vertonghen coming between strikes from Son Heung-Min and Fernando Llorente.
Dawson, who spent nine years at White Hart Lane between 2005 and 2014, was impressed by his former team’s display in the absence of some key performers.
“What an unbelievable second half,” he told Sky Sports.
“What a performance that has been. Did not see that happening. They’re in dreamland.
“If you’d have said at the start of the night: “Dele Alli not playing, Harry Kane not playing” and watching it in the first half, you’d have said this was going to be 3-0, I’d have laughed at you.
“There was no chance, in the first half there was only one team with the right mentality.
“In this second half Jan Vertonghen, he was super Jan Vertonghen, he was incredible with the goal, assist, he was up and down, kept (Jadon) Sancho quiet.”
The two teams will face off again in the return leg in Germany on March 5 at Dortmund’s Signal Iduna Park.
