Northern Ireland need to hand Switzerland a rare home defeat if they are to end a 32-year absence from the World Cup finals.
The Swiss are leading their play-off 1-0 after the first leg, with Ricardo Rodriguez's contentiously-awarded penalty in Belfast proving to be the difference on Thursday night.
Here we t profile the Swiss ahead of Sunday's return leg at Basel's St Jakob-Park.
Switzerland have won nine competitive games in a row at home and, disregarding friendlies, England are the only visiting country to have claimed a victory on Swiss soil since 2008. They did so twice - in 2010 under Fabio Capello, when current skipper Stephan Lichtsteiner was sent off in a 3-1 England victory, and then again with Roy Hodgson in charge at the start of their Euro 2016 qualification campaign. Danny Welbeck scored twice in September 2014, which was the last time the Swiss failed to win a competitive game at home.
Vladimir Petkovic, hired when Ottmar Hitzfeld retired after the 2014 World Cup, penned a fresh two-year contract extension over the summer having started with a perfect record in World Cup qualification. A former manager of Young Boys and Lazio, where he won the Coppa Italia, the Bosnia-born naturalised Swiss has done well to ensure the furore around Valon Behrami has not been a distraction for his team. Injured midfielder Behrami has remained with the Swiss camp despite his club Udinese demanding that he return.
It would be a surprise to see Petkovic stray too far from the 4-2-3-1 system that worked well in Belfast. His team utilised the full width of the pitch with full-backs Lichtsteiner and Rodriguez taking up advanced, wide berths, and Granit Xhaka was able to spread play with long diagonal passes. Northern Ireland did well to keep tabs on Xherdan Shaqiri for the most part, preventing him from cutting in onto his favoured left foot, but Blerim Dzemaili's movement behind Haris Seferovic caused them issues.
The most impressive player on display at Windsor Park on Thursday night was Borussia Monchengladbach 20-year-old Denis Zakaria, who along with Xhaka ensured Switzerland dominated the midfield battle. At one point in the first leg, Arsenal's Xhaka had completed more passes in Northern Ireland's half than their entire team had managed in the Swiss' half. Northern Irish boss Michael O'Neill has to be mindful that a bolder approach in Basel will leave space for Rodriguez and Lichtsteiner to operate in, which will possibly prevent him from lining up in a 5-3-2.