Krul made 14 saves to deny a host of Spurs players as the home side missed the chance to return to the top four at White Hart Lane.
The victory completed an impressive double for Newcastle, who beat Chelsea 2-0 last Saturday, with Krul ranking the performance as his best to date.
"This is the highlight of my career," he told Sky Sports.
"It was nice to celebrate with the back four. These kind of games don't happen very often, (it was) a great result."
The Dutchman's first save involved tipping a Roberto Soldado header over the bar from a set-piece, while Krul combined with Mapou Yanga-Mbiwa to prevent what looked like a certain goal following Christian Eriksen's free-kick and Younes Kaboul's follow-up.
"The first save was the best, Soldado's header," Krul continued.
"The sun was low and it kick-started from there. Mapou Yanga-Mbiwa put his life on the line to clear one and it shows the commitment, from the back five to the strikers.
"I think we have played better; against Sunderland we played well and lost. As long as we keep grafting, [Loic] Remy up front keeps scoring. If we keep a clean sheet we can win games.
"We know the Premier League is unforgiving. Two home games to go and we can look ahead with great confidence."