QEBERHA - South Africa, third at the AFCON this year behind hosts and winners Ivory Coast and Nigeria, matched a 5-0 scoreline against Guatemala in a 2010 World Cup warm-up as they outplayed Congo.
Teboho Mokoena, sidelined by Mamelodi Sundowns because of a dispute with his coach, showed no rustiness as he headed a corner into the net, then scored again via a half-volley.
Further goals from Bathusi Aubaas, who stretched the lead to 3-0 by half-time, Lyle Foster and substitute Iqraam Rayners completed the rout of a poor Congolese side.
The Group K match in Gqeberha was halted by the Mauritanian referee for 18 minutes during the first half after several spectators entered the pitch to join goal celebrations.
However, South Africa coach Hugo Broos warned his team to expect a much tougher return match in Brazzaville on Tuesday.
"Come tomorrow, our five-goal victory will be history. We have got to repeat the fantastic mentality shown tonight," said the Belgian who coached Cameroon to the 2017 AFCON title.
Uganda and South Africa have seven points each, Congo three and South Sudan none. The co-leaders can both clinch qualification if they win on Tuesday.