The much lower ranked New Zealand football team has been praised for holding Peru to a 0-0 draw in Wellington in the first leg of a world cup qualifier.  So the teams have flown to Peru for the second and deciding leg on Thursday.

New Zealand will still be underdogs, but they are in with a feasible chance.

NZH: What the All Whites need to do to qualify for the World Cup

They will be heading into Thursday’s second leg in Lima having kept a crucial clean sheet at home.

Here’s what the All Whites need to do to in the second leg to qualify for the World Cup in Russia next year.

Benefit from the away goals rule

The All Whites will progress to the World Cup finals with any kind of win on Thursday, whether it comes during normal time, extra time or penalties.

But thanks to the away goals rule, they could also make it through with a draw.

World Cup playoff ties are decided by the aggregate score over two legs. But in the event of a draw, the team that scores more away goals will qualify.

This means the only score that will lead to extra time and potentially penalties will be another goalless draw after 90 minutes.

By not conceding at home in the first leg, the All Whites will take a slight advantage into the second leg – knowing that any goals scored in Lima will also act as a tiebreaker.

If the score does remain 0-0 at the end of normal time in the second leg, the match will go into extra time where the away goals rule will still apply. If the match is still goalless after that, the tie will be decided by a penalty shootout.

So a draw will get New Zealand through as long as they score at least one goal. That will still be very difficult against Peru, as will limiting Peru to scoring no more goals than New Zealand, but the dream is alive.