Nigeria and Portugal progress, Brazil held again

Neymar's Brazil is still without a goal from its opening two Group A games of the tournament, held to another 0-0 draw, this time by Iraq.

Nigeria celebrates its win over Sweden.

Nigeria and Portugal became the first teams to qualify for the Olympic men's football tournament quarter-finals, while host Brazil was held again. 

The 2008 runner-up Nigeria backed up its thrilling 5-4 win over Japan with a 1-0 victory against Group B opponent Sweden, courtesy of Sadiq Umar's first-half goal. Portugal, which defeated Argentina in its Rio 2016 opener, made it two wins from two in Group D on Sunday with a 2-1 come-from-behind triumph against Honduras. 

Neymar's Brazil is still without a goal from its opening two Group A games of the tournament, held to another 0-0 draw, this time by Iraq.

Denmark boosted its chances of progression to the next round with a tense 1-0 win against South Africa, while Argentina got off the mark in Group D with a 2-1 victory over Algeria. 

Germany scored late through Serge Gnabry to salvage a 3-3 draw with South Korea in Group C, and Japan battled from two goals down to secure a 2-2 draw against Group B rival Colombia. 

Meanwhile, Fiji scored its first ever Olympic goal in its Group C clash with Mexico, but despite leading at half-time went down 5-1 to the defending champion. Wellington Phoenix forward Roy Krishna made history with Fiji's first goal at the Olympics, heading the South Pacific nation into a 10th-minute lead.  However, Mexico struck back in the second period, with Erick Gutierrez scoring four of its five goals in a 5-1 win.