Portsmouth managed to beat Liverpool 2-0 on Saturday.
O’Hara is looking to extend his loan from Spurs until the end of the season.
“We’ve been threatening a result like this. Everyone wrote us off, but no-one in the dressing room thinks we’re going down,” he said.
“Maybe something isn’t quite gelling in the Liverpool team. They lost a couple of good players and it’s difficult to replace the quality of people like Xabi Alonso.
“You can never write them off and I still fancy them to be challenging for a Champions League spot, but nobody likes to get hounded.
“We knew we had to get after them. If you give Steven Gerrard too much space he’ll cause a lot of trouble, so we knew our five in midfield would have to hustle.
“Over the years, no-one has enjoyed coming to Fratton Park because of the atmosphere and we didn’t give Liverpool time to settle – that’s how you have to play against these big clubs.”
