Panama or Honduras loom as the most likely opponents for Australia should the Socceroos progress in their World Cup playoff tie against Syria.
After Costa Rica's last-gasp goal to snatch a 1-1 draw against Honduras and seal a World Cup finals berth, Panama or Honduras look set to battle it out for fourth in the Central/North American zone.
The Socceroos will be trying to advance to the next stage of the playoffs when they play Syria in Sydney on Tuesday night.
Costa Rica's dramatic late goal means the United States need at most a draw at Trinidad and Tobago on Tuesday night to qualify for their eighth-straight World Cup berth.
Costa Rica have 16 points and are second in the final round of North and Central American and Caribbean region qualification, behind Mexico, who have 21 points and clinched a World Cup berth last month.
The US have 12 points following their 4-0 win Friday over Panama and would qualify with a win or draw in Trinidad on the final night of the qualifiers. Panama and Honduras have 10 points each.
Goal difference has become key: the US are plus-five, Panama minus-two and Honduras minus-seven meaning the Americans should only need a draw to go through.
In addition, the US could qualify with a loss if Panama and Honduras both fail to win on Tuesday.
The Americans would be eliminated only if they lose and Panama and Honduras both win.
Kendall Waston scored in the fifth minute of second-half stoppage time to clinch Costa Rica's second-straight World Cup berth and fifth overall.