Blitzbokke coach Paul Treu was delighted and relieved after his side won their first Sevens World Series tournament in two seasons on Sunday.
South Africa beat series leaders New Zealand 40-21 in the Cup final on the third and final day of the USA Sevens in Las Vegas.
"I'm just so glad for the guys," said Treu.
"They deserve this win because they work so hard during training."
Two Chris Dry tries and further five-pointers from Warren Whiteley and Branco du Preez - which were all converted - in an action-packed opening period gave South Africa a 28-0 lead at half-time.
Two more tries after the interval, scored by Du Preez and Stephan Dippenaar, stretched the total to 40 points.
The Kiwis hit back late in the second half, scoring three tries through Pat Lam, Tim Mikkelson and Gilles Kaka, but the Blitzbokke held on to win the Las Vegas tournament for the second time in three years.
South Africa had earlier defeated Samoa 12-7 in extra time in their cup semi-final.
Cornal Hendricks scored a try to put the Blitzboks ahead as early as the third minute, which was converted by Du Preez, but Tulolo Tulolo hit back for Samoa shortly before the half-time break.
Lolo Lui missed a penalty for the Samoans in second-half injury time, and with scores remaining level at 7-7, the match was extended to sudden death extra time.
Seabelo Senatla dived over a little more than a minute after the restart to secure the win.
"We set such a high standard for ourselves and we need to come out and perform like that every time," said Blitzbokke veteran Paul Delport.
"This is huge for us. We put in so much effort back home -- there are just no words to describe this winning feeling."
The next tournament, another three-day event, will be played in Hong Kong starting on March 22.