"We can win in Port Elizabeth. As soon as your belief goes it is going to be a difficult mountain to climb," admitted Lancaster.
"We know we've got to be better in all the little details that make the difference in winning at international level. Our boys have had an 11-month season now - it was probably this time last year the World Cup camp started.
'We went through that, the World Cup, the Six Nations - it has been a long slog - but I guarantee there is one more game left in them.
'The good thing is the overriding feeling in the dressing room was frustration. I would be disappointed if the players came in and said, 'We did a good job and almost won'.
'Great sides want to win all the time and these players are hungry. We'll bottle the frustration, drive it through training this week and then have a crack at it in Port Elizabeth."
Having lost the first Test 22-17 in Durban, England conceded early points and found themselves 22-3 down in the first quarter at Coca Cola Park. But a breakaway try by Toby Flood, and two scores from his Leicester Tigers half-back partner Ben Youngs, got England back into the game.
"I thought our scrum began to take control and gain the ascendancy in the second half. When we had the ball, and we moved it, we definitely caused them problems defensively," said Lancaster.