For the first time, teams this year are fighting for a spot in a one-off tournament labelled "the World Cup of tennis" by the ITF.

Previously Davis Cup ties have taken place periodically throughout the season, but this year a new format will see 18 nations battle it out at the Davis Cup Finals in Madrid from November 18 to 24.

The 2018 champions Croatia, runners up France and semi-finalists Spain and the United States are already guaranteed a spot in the Finals, as are Argentina and Great Britain who have each been given wildcards.

This week’s qualifiers are taking place to fill the remaining places at November’s event, with Slovakia versus Canada, China versus Japan and Australia versus Bosnia Herzegovina among the ties.

With two singles rubbers going ahead today in each tie, in Slovakia Canada’s Denis Shapovalov put his country in the lead initially with a 6-4, 7-5 triumph against Filip Horanský at the NTC Arena in Bratislava.

In another change to the Davis Cup, matches will now be best of three sets and not best of five.

Slovakia then threw level though, when Martin Kližan beat Felix Auger-Aliassime 7-5, 6-3.

In Australia’s tie at the Memorial Drive Tennis Club in Adelaide the hosts went 2-0 up on day one thanks to wins from John Millman and Alex De Minaur in the first singles rubbers against Bosnia Herzegovina.

Millan saw off his opponent Damir Džumhur 6-3, 6-2, before De Minaur beat Mirza Bašić 6-3, 7-6.

In China at the Guangdong Olympic Sports Centre day one ended with the hosts and Japan locked at 1-1.

China initially went ahead when Zhe Li beat Yoshihito Nishioka 6-3, 6-2 before Daniel Taro levelled the tie by winning the second rubber 7-6, 6-4 against Ze Zhang.

Japan’s top ranked player Kei Nishikori is not taking part.

Elsewhere, even without the talisman and recent Australian Open champion Novak Djokovic, Serbia went 2-0 up on Uzbekistan at the Saxovat Sport Servis Sport Complex in Tashkent.

Dušan Lajović won the first singles rubber 7-6, 6-3 against Sanjar Fayziev before Filip Krajinović beat the 2018 Asian Games champion Denis Istomin 6-2, 6-4.

Playing India, Italy went 2-0 up on their opponents at the Calcutta South Club thanks to wins from Andreas Seppi and Matteo Berrettini and at the National Tennis Centre in Astana Kazakhstan took a 2-0 lead against Portugal.

They won both matches today thanks to Alexander Bublik and Mikhail Kukushkin.

Over in Switzerland, without the great Roger Federer, the hosts went 2-0 down against Russia at the Swiss Tennis Arena in Basel.

The two singles rubbers there today were won by Daniil Medvedev and Karen Khachanov, while it is one all in Austria after day one between them and Chile.

At the Salzburg Arena Nicolas Jarry won the first rubber for Chile before Dennis Novak took the second for Austria.

Play in the tie between the Czech Republic and The Netherlands also ended today at 1-1.

Playing at the Ostravar Arena in Ostrava, Jiří Veselý put the hosts ahead before Robin Haase drew the visitors level.

Meanwhile, at the Fraport Arena in Frankfurt, Germany won both singles rubbers to go 2-0 up on Hungary.

Philip Kohlschreiber took the first in a tight three set match before the 2018 Association of Tennis Professionals World Tour Finals champion Alexander Zverev comfortably won the second.

In Uberlandia in Brazil the score between the hosts and Belgium is 1-1 after the first day.

Thiago Monteiro put his side in the lead initially  with a straight sets win before Kimmer Coppejans drew the match level with a straight sets victory of his own.

Lastly in Colombia at the Palacio de los Deportes the hosts went 2-0 up on Sweden.

Santiago Giraldo took the first rubber before Daniel Elahi Galan Riveros won the second for the loss of just three games.