"Given the mood around Newcastle we knew the first goal could help us," added O'Hara, after Roman Pavluychenko headed the visitors in front.
"Both teams were low on confidence going into the game and the season hadn't really started well for either of us.
"But we've gone three games unbeaten now and we're really looking to push on. We've got another good result from a tough game. They came at us but we looked strong at the back."
Former Newcastle favourite Jonathan Woodgate is key to that defensive solidity and the England centre-half was in imperious form against his old club.
But it was O'Hara who proved the perfect link man between defence and attack and his quick thinking, to rob United's Steven Taylor, led to Spurs' decisive goal.