A first-half goal from Luis Suarez was enough to help Uruguay secure top spot in Group A and progress into the last 16 of the World Cup after a close victory over Mexico, who also qualified.
The only goal came two minutes before half-time when Edinson Cavani's superbly floated cross allowed the Ajax striker to head in at the back post.
With hosts South Africa unable to alter the goal difference too much in their 2-1 win over France, the result in Rustenburg also put the nervous Mexicans through.
Their coach Javier Aguirre made two changes to his line-up, bringing in veteran Cuauhtemoc Blanco for his first start in place of the injured Carlos Vela up front, while Andres Guardado was in for the suspended Efrain Juarez.
Uruguay also made one surprise change, with Diego Godin dropping to bench in place of Mauricio Victorino.
There was a buzz in the Royal Bafokeng Stadium at the start, with most of the noise coming from the fans in green, who outnumbered those in blue.
But the Mexicans and their supporters were almost silenced early on.
First Maxi Pereira saw his rising 30-yard free-kick fly over, and then an error from Hector Moreno allowed Suarez in but the striker only managed to send his shot across the face of goal.
El Tri had a good chance moments later when Giovani dos Santos crossed for Blanco, but the 37-year-old headed over.
After 15 minutes Victorino managed to find space from a corner but nodded his free header over, before Alvaro Pereira drilled his shot wide after racing down the left - much to the fury of the unmarked Diego Forlan in the box.
Midway through the half, Guardado almost stunned Oscar Tabarez's side with a wicked 30-yard effort that beat Fernando Muslera, but not the underside of the crossbar.
At the other end, Oscar Perez punched weakly at a Forlan cross, but there was no one following up at the back post.
The chances seemed to dry up 15 minutes before the break, but then Suarez broke the deadlock.
Aguirre decided to make a change at the break, bringing Pablo Barrera for Guardado.
And his side had the first chance of the half courtesy of a Blanco free-kick 25-yards out that was curled into the arms of Muslera.
Uruguay then almost doubled the advantage when Forlan swung over a free-kick from the right, but Diego Lugano's powerful header drew an excellent low save from Perez.
In another attacking move, Israel Castro and Javier Hernandez were thrown in, but it was a defender, Francisco Rodriguez, that had a golden opportunity to equalise from Barrera's cross, which was a glanced header that ended up wide.
Hernandez was next to have a chance, but it was only a half one as he found little room to try and get away a shot in the six-yard box, with the ball deflected for a corner.
The Mexicans again had their goalkeeper Perez to thank in the 87th minute when he parried away and awkward 30-yard Cavani strike for a corner.
It proved the last chance for either side as La Celeste held on.