Border beat the Golden Lions 24-13 on the opening day of the U16 Grant Khomo Week at Grey College in Bloemfontein.
The young Bulldogs outscored their opponents by four tries to two.
Meanwhile, Free State scored 12 tries in their 71-19 thrashing of Zimbabwe, having led 45-0 at half-time.
The Griffons crossed the line 11 times in their 69-13 victory against Border Country Districts, with winger Mpho Ntsutle and No 8 Keke Morabe each scoring a hat-trick.
The Limpopo Blue Bulls ran in eight tries to secure a 48-19 victory against the Valke, while SWD beat the Pumas 39-23. SWD No 8 Hendrick Victor and Pumas winger Michael Dlamini each scored a brace.
Western Province beat the Blue Bulls 36-17 after the teams had been level at 14-14 after a tight first quarter. Province went on to score five tries in what was ultimately a comfortable win.
Namibia fought back from 17-14 down at half-time against the Leopards to win 31-23, the Free State XV edged Eastern Province 24-21, having trailed 13-3 at the break, and Boland kicked a crucial penalty goal to beat Griquas 17-14.
KwaZulu-Natal snatched a 15-14 victory in the last minute of their clash against the Western Province XV.
U16 Grant Khomo Week results (Day 1):
Border 24 Golden Lions 13
Namibia 31 Leopards 23
SWD 39 Pumas 23
Griffons 69 Border CD 13
Eastern Province 21 Free State XV 13
Western Province 36 Blue Bulls 17
Boland 17 Griquas 14
KwaZulu-Natal 15 Western Province XV 14
Limpopo Blue Bulls 48 Valke 19
Free State 71 Zimbabwe 19