Brazil crushed Puerto Rico on Thursday after Argentina had done the same to the Dominican Republic on the final day of group play at the 2011 FIBA Americas Championship in Mar del Plata. Now, the South American powers will swap foes as the semifinal bracket between the four nations gets underway on Saturday.

Brazil is now the top seed in the tournament, having beaten Argentina by two points on Wednesday and Puerto Rico by 22. The Brazilians, missing three of the teams four NBA players, have just one loss in this tournament through eight games. But it came against the team standing between them and a berth to the 2012 London Olympics: the Dominican Republic.

The D.R. has struggled since beating Brazil in the first group stage. The 79-74 Dominican victory on Sept. 2 set John Calipari's team as the top seed out of Group A moving into the combined group stage. But at that point, after beating Panama handily, the D.R. struggled to finish off Uruguay and was blown out of the water by Puerto Rico and Argentina to send them to the No. 4 seed. The team's starting frontline -- the Atlanta Hawks' Al Horford and international player Jack Michael Martinez -- have played well. But Charlie Villanueva and Francisco Garcia have been inconsistent (to say the least) and the team seems to be missing Edgar Sosa, who suffered a horrific injury in the win over Panama.

Argentina is the most fully stocked team in terms of NBA talent, with Manu Ginobili, Andres Nocioni, Carlos Delfino and Luis Scola leading the way. The Argentines' sole loss of the tournament came in a two-point defeat to Brazil on Wednesday; the continental rivals also played a classic nailbiter in the Round of 16 at the 2010 FIBA World Championships in Turkey a year ago. No one would have blamed Ruben Magnano's team if it had folded in this tournament, missing Nene, Leandro Barbosa and Anderson Varejao. But Brazil hasn't let up, and just needs to avenge its loss to the D.R. to claim a spot in the Olympics.

Argentina-Puerto Rico figures to be a screamer, too, provided that the P.R. plays much better than it did against Brazil on Thursday. In the first group stage, Argentina beat Puerto Rico 81-74 behind 23 points from Manu.

Dominican Republic vs. Brazil tips at 6 p.m. ET on Saturday. Argentina vs. Puerto Rico follows. The bronze and gold medal games will be played Sunday, with the championship match scheduled for 8:15 p.m. ET.