The BlitzBoks will face Fiji in the Cup semifinals at the Dubai Sevens.
The South Africans beat Samoa 26-10 in their quarterfinal on Day Two, while Fiji beat Scotland.
New Zealand and England will meet in the other Cup semifinal.
Cup semifinal fixtures:
South Africa v Fiji
New Zealand v England.
South Africa 26-10 Samoa
South Africa made the perfect start with Seabelo Senatla going over for the first try after a minute of play.
However, the Samoans hit back with a brilliant try to level the scores midway through the first half.
It did not take long for the South Africans to regain the lead with Senatla going over for his second try a minute before half-time.
Samoa needed to be the first to score in the second-half and their physicality helped them over the tryline inside the first two minutes.
However, the BlitzBoks hit back almost immediately with a Werner Kok try to push the lead out to nine points after the conversion.
That lead was increased when Tim Agaba crashed over for a try to take the game away from the Samoans.
Fiji 35-24 Scotland
There was plenty of entertainment in the first half between these two teams. Fiji took and early with a try before Scotland surprisingly scored two tries against the run of play.
However, Fiji finished the half the stronger of the two teams with another three tries to go into the break with the score at 28-12.
Scotland outscored the Fijians by two tries to one in the second half, but it was not enough and Fiji marched on to the semis.
New Zealand 14-12 Kenya
New Zealand opened the scoring, but it was all Kenya for the rest of the first half as the Africans ran in two tries to go into the beaking leading 12-7.
Kenya held onto their lead for most of the second half before New Zealand scored a converted try near the end to snatch victory away from the Kenyans.
England 26-19 Australia
The first half was a hard-fought encounter with the scores level at 12-12 after both sides crossed the tryline twice.
The second half was just as tense with both teams locked at 19-19 with less than 90 seconds remaining.
However, England snatched victory at the death with a brilliant try to send them into the semifinal.
Challenge Tropy quarterfinals:
Canada 10-5 USA
After Canada dominated play for most of the first half, it was the USA who took the lead just before half-time with a try by Ben Pinkelman.
Canada continued to dominate play in the second half and they were eventually rewarded when they went over for a score in the corner to level the scores with three minutes left.
The match eventually went into extra time with Canada eventually getting the winning score.
Wales 17-24 France
Wales and France produced some excellent rugby in their match with both sides scoring two tries in the first half. However, it was France with a narrow 14-12 lead at the break as all their conversions were successful.
France were the better team in the second half and they pulled away with another two tries with Wales only grabbing a solitary late score.
Argentina 26-7 Uganda
Argentina were well in control in the first half outscoring their opponents by three tries to one to go into the break 19-7 ahead.
There was only one try in the second half and that went to Argentina who eventually won 26-7.
Spain 31-0 Russia
In the battle of the minnows, it was all one-way traffic with Spain outplaying Russia in all facets of play.
At half-time Spain led 21-0 after three converted first-half tries.
Spain continued where they left off in the first half when they ran in another two tries in the second half to win 31-0.