The Foxes secured their third successive league win after Perez turned the ball into his own net in the 86th minute.
Joselu had fired Newcastle ahead after four minutes before Riyad Mahrez and Demarai Gray turned the game on its head, and though Dwight Gayle levelled for Newcastle, Leicester took all three points in fortuitous circumstances.
Puel praised his Leicester players for handling the atmosphere under the lights at St James' Park.
He said: "I think we deserved this win witha fantastic positive attitude. It was a difficult game - we had to play against Newcastle
and against this atmosphere, and it's always difficult to play, to resist sometimes under pressure.
"The second goal gave us the lead, but it was difficult, but a draw would have been difficult to accept, so my team deserved the
third goal with a fantastic and positive attitude."
Puel reserved particular praise for Japan international Shinji Okazaki, who forced the winner after playing on following a head wound which left him swathed in
bandages.
He said: "The first example is Shinji - he is a kamikaze and it's a good thing for the team. He's a fantastic player with fantastic
spirit and all the squad like him because he gives everything and he also gives his body for the team."