South Africa desperately needed a win to regain their confidence after five successive test defeats, plus a poor World Cup, and beating England in the first test on Sunday was just the tonic, said captain Faf du Plessis.
"It's been a tough year for the test team and it's been a while since our last victory but we trained hard and there was a good feeling in the camp that we had done some really good preparation before the test match," he said after the home side's 107-run victory to go ahead in the four-match series.
"We knew we needed to put in some performances to get the engine running and I thought that, in all departments, we were really good in this test match.
"England were good at stages as well, but the way we played, especially in the last two days when the wicket did get a little bit flatter, the way the guys' skill was remarkable and consistent all the time, made it a good start.
"That's what we needed: a good start to get our confidence back as a test team. We are very happy as a test team as we sit here now."
South Africa last won a test in their 3-0 series victory against Pakistan in January but then lost 2-0 at home to Sri Lanka and were comprehensively thumped in India in October.
"As a team we don't have a lot of superstars and as a team you take a lot more from victories where everyone contributes in their own way," Du Plessis added.
He pointed to 40 runs in the second innings from nightwatchman Anrich Nortje as an example.
"That was really pleasing because those are the things that lift a team.
"Our bowling unit was exceptional. All of them put their hand in when the wicket didn't dry out and they needed to be top of their game," he added.
South Africa take on England in the second match at Newlands, from Jan. 3-7.