A packed arena got its fill at first.
Mexico took the lead early when Julián Quiñones made it 1-0 in the ninth minute after the home team had created a big chance.
Mexico, 14th in the world rankings, were huge favorites against 60th-ranked South Africa, and there was a clear class difference in play.
However, it was not entirely one-sided.
After unfortunate South African defender Sphephelo Sithole - who lost the ball before the 1-0 goal - was sent off in the 49th minute, the home team seemed likely to secure the victory.
As little happened, home fans began to impatiently boo the green-clad home team.
However, Raúl Jiménez was able to silence the boos when he headed home to make it 2-0 in the 67th minute.
Discontent turned to jubilation at the iconic Azteca Stadium in Mexico City, which became the first stadium in the world to host three World Cup opening matches.
Mexico, which is co-hosting the World Cup with the United States and Canada, was the sole host of the World Cup in 1970 and 1986.
South Africa suffered another sending-off when Themba Zwane was shown a red card in the 84th minute after a VAR review, but the home team was hit when César Montes was sent off in added time.
