The Foxes dominated throughout against previously table-topping Brighton and deserved more than their 46th minute winner which arrived when Japan midfielder Yuki Abe headed home a Darius Vassell cross.
Eriksson said: "I'm very happy with the performance and result. I thought we performed very well for 90 minutes, finally.
"That was the real Leicester City which we had not seen perform previously over a full 90 minutes. The closest we had seen it was for 60 minutes against Forest when we led 2-0 but allowed them to draw.
"We played the number one team in Brighton and we were the better team. We stood up to a good technical team who were well organised and very quick to attack"
And the Swede lavished praise on strikers Jermaine Beckford and Vassell.
He said: "Our front two worked very hard. They are not easy to defend against. For the goal Vassell's cross was excellent
"Beckford was calm, clever and didn't give the ball away."
Eriksson said he was unhappy that referee Graham Scott had ruled out a Lee Peltier goal.
The Oxfordshire official disallowed the full-back's effort because a second earlier he had blown for a foul on Darius Vassell. Leicester claimed angrily that the referee should have played advantage and allowed the impressive strike to stand.
Eriksson said: "The referee was too quick. Where the referee was stood, he must have seen Peltier coming. He should have waited a couple of seconds."
And the former England boss shrugged off rumours that City's indifferent start to season had put his job at the King Power Stadium in jeopardy.
He said: "I've been under pressure for 30 years or more. It's always like that, but expectations about this team are very high. We have big goals. It is not something that worries me at all."
Brighton boss Gus Poyet conceded his previously unbeaten side were poor.
He said: "We were not good enough technically today for some reason. We were chasing the game. Overall we were not good enough.
"We made too many bad decisions. We slowed the game down too much and played too direct."
Brighton's only two real chances fell to the usually reliable Craig Mackail-Smith, and he missed them both..
Poyet said: "Another day Mackail-Smith might have scored, but you can't expect for every game to go your way.
"But if someone had told me that we would have started the season unbeaten until our seventh game I would have taken it."
And Poyet was upset by the sending off of Marcos Painter for two bookable offences.
Poyet said: "I felt sorry for Marcos because for one foul and one handball he is now going to miss the big game at home to Liverpool, is that fair?"