The last two places at the World Cup finals will be decided this week, with Australia, New Zealand, Peru and Costa Rica digging into their stamina reserves for do-or-die battles.
Both international playoffs are single-leg showdowns in the Ahmad bin Ali Stadium in Doha, a 40,000 capacity venue that will host matches in the World Cup finals in the autumn.
Australia take on Peru on Monday. New Zealand face Costa Rica 24-hours later.
All four nations are used to the last-chance scrap for a World Cup place.
Four years ago Peru beat New Zealand 2-0 to clinch a slot at Russia 2018 where they beat Australia in the first round group - their first World Cup win in four decades.