After Spurs missed several glaring opportunities, Harry Kane pulled a goal back in the 79th minute but the visitors were unable to avoid a third defeat in five league games following another subdued display.
"In the Premier League if you do not fight you are going to struggle, and our performance was a clear example of that in the first half when we were 2-0 down," Pochettino told reporters.
"I think in football, first of all you must compete, fight and be focused, and then of course the quality will come through. But Leicester showed more than us and were ready to fight.
"It was difficult to analyse the game because we started so sloppily. Our performance in the first half disappointed us a lot."
The defeat leaves Tottenham 13 points adrift of league leaders Manchester City in fifth position and the north London club could fall further down the standings after Wednesday's fixtures.
Leicester registered their second league win under manager Claude Puel, who was appointed late last month, to climb to ninth in the standings and the Frenchman is optimistic about the side's future.
"It was a big win with quality. It was a fantastic game for us," Puel said. "The goals from Jamie and Riyad were fantastic and this is amazing for the future.
"It was a very good game and it's important to continue this hard work on the pitch in the training sessions. It's just one game but it's promising."
Tottenham travel to Watford on Saturday while Leicester host Burnley.
(Reporting by Aditi Prakash in Bengaluru)
