Heyneke Meyer praised South Africa's attitude as they came from behind to beat Australia 28-10 in the Rugby Championship on Saturday.
Three tries in the final nine minutes saw the Springboks earn a much-needed bonus point and apply some pressure on New Zealand at the top of the table.
The All Blacks saw their lead cut to just a point but can still secure the title with victory over Argentina in Buenos Aires.
South Africa are guaranteed second place with the win over Australia and were Argentina to cause an upset, there would be a title decider in Johannesburg next weekend.
The Springboks spent a large part of the match against the Wallabies behind but a Patrick Lambie drop goal sparked them into life with 11 minutes remaining and the try blitz followed, with captain Jean de Villiers grabbing a brace.
Meyer was delighted to see South Africa's will-to-win remain strong despite staring defeat in the face, and he praised their fitness levels to complete the comeback.
"We played great rugby at times in the first half, but their defence was great," said the Springboks' coach. "We became a bit frustrated because of that, but in the second half the fitness levels and impact from the bench was massive for us.
"We wanted to make our country proud and hopefully [we] managed that. We battled at times, but I have to say that our captain [De Villiers] led from the front and came through for us.
"The team also refused to give up. They sprinted back to our line after the third try, wanting to get that fourth one, and we managed that. We scored some great tries when we finally managed to break them down."
Captain De Villiers believes the Springboks can use the momentum from the win to beat New Zealand at Ellis Park.
"We will take all the good from this match into next week," said the centre. "We came so close to beating New Zealand in Wellington [a 14-10 defeat] and I think we can be very competitive next weekend at Ellis Park.
"We didn't play badly in Perth and Wellington. We did many good things there.
"Tonight was an improvement on that and next week we have to step up again. If we continue this, we can beat New Zealand next week."