Venezuela's Gabriel Maestre has progressed to the quarter-finals of the Olympic welterweight class courtesy of a five-point victory over Siphiwe Lusizi of South Africa.

There was not much between the two fighters in the first round, which the South African just shaded 4-3.

Maestre started brightly in the second round and began letting his fists go, using his dangerous left hook to repeatedly knock Lusizi off balance.

The Venezuelan has battled back well in the second to lead by four points, aided in part by the referee, who gave Lusizi a public warning.

Lusizi tired by the third round and could do nothing to stop Maestre taking a 18-13 decision.