Spurs looked on course for a valuable point at Anfield after Lucas Moura had cancelled out Roberto Firmino's early header.
But in the 90th minute, Hugo Lloris parried Mohamed Salah's header against Toby Alderweireld, who could not react in time to prevent the ball rolling into the net.
While the win sends Liverpool back to the Premier League summit, it leaves the north Londoners facing a battle to hold onto their top four berth.
"In the second half we dominated a team like Liverpool," he told Sky Sports. "It is not easy to come here and dominate them.
"After the first half we conceded a goal when there was not too much happening in the game. That was tough for us but in the second half we started playing with a lot of confidence.
"It is very tough to lose the game in that way but I feel I am happy because the emotion and feeling we have got today will help us.
"It is now a mini-league - seven games and we are in the top four. It is in our hands.
"In the circumstances, they [the Tottenham players] are more than heroes. We need to keep our trust and confidence and we will fight to be in the next Champions League.
"It is so important for the club to be in the top four at the end of the season."
It remains to be seen if Tottenham's imminent move into their new stadium will have a factor on their pursuit of a top-four finish.
But Pochettino has warned his players they must cope with what is sure to be an emotional occasion on their return to home turf after nearly two full seasons at Wembley.
He added: "It's so important to manage the energy, a lot of emotion is going to be there.
"We need to understand that the players after a defeat can still believe. I am very happy with how they are behaving and their commitment. We are arriving at the last seven games with the possibility of a top-four finish and it's in our hands to be there.
"They must think they are heroes, but we must be sure how we are going to spend our energy. Now it's about recovery and being clever."