Beijing:Argentina and Brazil remained on course for a semi-final showdown in the men's Olympic football competition as the final eight sorted themselves out in the last round of Group matches on Wednesday.
Italy emerged as the best of the rest and have the kindest draw with the prospect of a semi-final against Nigeria if the Group winners also win their opening play-off match.
Defending champions Argentina kept Lionel Messi on the bench but were still too good for Serbia for their ninth consecutive Games win, an Olympic record after going through unbeaten in Athens four years ago.
They beat the Serbs 2-0 with a penalty by Ezequiel Lavezzi in the 12th minute and a free kick from Angel de Maria more than an hour later.
A goal from Chelsea striker Salomon Kalou gave Ivory Coast a 1-0 win over Australia to qualify second in Group A and an African showdown with Nigeria in the quarter-finals.
Argentina play the Netherlands in the quarter-finals while Brazil play Cameroon.
A brace from Thiago Neves helped Brazil to beat China 3-0 ending any hope the host nation had of going through.
Such was the pressure on the Chinese to perform that their one point from three games drew the ire of their fans with one online commentator describing their performances as "full of shame and disgust".
But they were never in with a chance against Brazil who have Ronaldinho back to his near best dictating the game from the midfield.
Belgium beat New Zealand 1-0 to be the second qualifiers from group C and a date with Italy.
They Italians and Cameroon both progressed to the quarter-finals after fighting out a turgid goalless draw in Group D which saw the African side play with 10 men for all but 32 minutes.
Whilst Cameroon - who also missed a penalty - will be pleased to have made the last eight, the 2000 Olympic champions will be missing the red carded Georges Mandjeck and defender Paul Bebey - who received his second yellow card of the tournament - when they play Brazil.
Nigeria finished top of Group B when they beat the United States 2-1 with the Netherlands leapfrogging the USA to be the second qualifiers when a late Gerald Sibon penalty secured a 1-0 win over lowly Japan.
America's cause was not helped by playing with 10 men from the second minute when defender Michael Orozco was red-carded.
The quarter-final matches will be played on Saturday.