Robbie Keane had put the visitors ahead in the 32nd minute of this Premier League contest by clipping a left-footed shot past Joe Hart.
However, just before the hour Stephen Ireland poked home from close range before Nedum Onuoha's powerful 72nd-minute header clinched a first victory since the Manchester derby on February 10.
Ireland's strike ended a six-hour 14-minute goal drought stretching back to that success over United and provided the catalyst for a much-improved display from Eriksson's previously struggling side.
"It was extremely important for us, we had had three games with no goals and three games with one point," said Eriksson.
"I don't think we played badly in the first half but we should have been more lively and shown less respect.
"I think we did it in the second half and scored two goals. I think if you look at the game we deserved to win it."
There was a suspicion of offside about Ireland's goal, while Tottenham had a late Darren Bent goal ruled out by the assistant referee's flag when it was Dimitar Berbatov who was the offending player further over.
However, Eriksson said it was about time his side had some good luck.
"I don't remember when the linesman helped us the last time - it has been many times for the opposition," said the Swede.
"I don't know if he did this time but I think we deserved to win, we created more chances than they did."
On Ireland's goal he added: "It's very difficult to see. Even if it is offside I think Spurs owe us one or two offsides."
Spurs boss Juande Ramos felt his players eased up after going in at half-time 1-0 up.
"We were so much in control of the game it maybe made our lads think that maybe the game was won before it was over," he said.
"We were finding everything quite easy up to that point. I think the equaliser had two benefits: it picked them up and maybe then we struggled to keep control of the ball from that moment.
"The second goal was definitive because it decided the game and it was difficult to pick things up after that."