Switzerland are yet to drop a single point in the qualifying campaign, but defeat today could force them to go through the play-offs in order to make it to Russia next summer. A win for Portugal will bring them level on points with the Swiss, but the reigning European champions boast a far better goal difference that would push them ahead, having scored 30 times in 10 matches.
Half of those goals have been the work of Cristiano Ronaldo, who came off the bench against Andorra to score his 15th of the qualifying campaign. In the final fixture in Lisbon, he will be looking to find the back of the net again, not only to clinch a crucial win for his team, but to continue his record-breaking form.
One more goal will equal the record set last week by Robert Lewandowski of most goals scored in European qualification (16), but it will also allow him to become one of the all-time top three goalscorers with their national teams.
Having netted an impressive 79 times in 176 appearances with Portugal, he is about to break into the podium of all-time best strikers at international level. Having left Pele (77) behind, the 32-year-old is currently level with legendary Zambia centre-forward Chitalu (also 79).
He has only three more players to beat on his way to the top and he could draw level with one of them tonight: Kamamoto, who scored 80 goals for Japan. After that, he will endeavour to outscore Ferenc Puskas (84), and the slightly out of reach Ali Daei (109), who banged in the goals for Hungary and Iran, respectively.