The Bundesliga side stunned Atletico Madrid at the Estadio Jose Alvalade on Thursday night to book a place in the last four of Europe’s premier club competition.
Leipzig drew first blood after Daniel Olmo headed home a Marcel Sabitzer cross five minutes after the break.
Atletico record signing Joao Felix pulled parity for the Spaniards from the penalty spot on the 71st minute mark.
Diego Simeone’s side looked like they were the most likely to get the win in normal time but Tyler Adams got the winner for Leipzig during the dying embers of the game.
Speaking after the game, Nagelsmann reflected on his team’s performance against a side he knew would defend.
"It was a good game. Atletico defended like in all games - very good,” the German coach told reporters.
“At the end we were better in the final third. We did not create many chances, but they didn't create many chances.”
"Great emotions for the club and our team. As a manager you have to look forward. We have to prepare for the next game.”
“There's not a lot of time to celebrate but maybe we will have a beer in the hotel then we focus on PSG.”
The former Hoffenheim boss admitted his side will not get it easy when they come up against Thomas Tuchel’s men in the semi-final.
The 33-year-old added: “We have to be very fast along the defence line. There will be situations where you cannot defend against these guys on your own. Atalanta tried to defend one on one. There are a lot of stars in this team - it won't be easy."
