The Foxes took advantage of a poor first half showing from Mauricio Pochettino’s side as Jamie Vardy and Riyad Mahrez both bagged spectacular goals before the break.
Spurs rallied somewhat in the second half with Harry Kane pulling one back, though Christian Eriksen and Fernando Llorente scuppering golden chances either side of the goal meant Spurs left without as much as a point.
The defeat leaves them 13 points adrift of leaders Manchester City, who play Southampton tonight, but Alli says they must simply move forward.
"It was a very disappointing performance from us in the first half,” Alli told BBC Sport.
“We should never have been in the situation where we were two goals behind. It was not good enough.
"We can't focus on that. After performances like this we have to keep picking up points. To lose to Leicester away is disappointing but we have to pick ourselves up.
"We have to keep performing. It is a long season and we just have to keep picking up points."
