The biggest upset of the group stages saw debutants Finland shock 32-time champions United States yesterday in Group D.

A sensational performance from Otto Virtanen saw the Finnish star save two match points in the decisive tie breaker to defeat Mackenzie McDonald 7-6, 1-6, 7-6.

Meanwhile, Tommy Paul suffered at the hands of Emil Ruusuvuori, going down 6-7, 4-6.

They were joined by the Netherlands from the group as they head to last eight stage in Malaga in November while Croatia were knocked out.

Sunday's action saw Britan punch their ticket thanks to Dan Evans and Neal Skupski.

The duo saved four match points in a nail-biter against Nicolas Mahut and Édouard Roger-Vasselin 1-6, 7-6, 7-6 in Manchester.

Earlier, Evans got the better of French teenager Arthur Fils 3-6, 6-3, 6-4.

However, British number one Cameron Norrie was not up to the challenge, going down to Ugo Humbert 7-6, 3-6, 7-5, led to the all-at-stake doubles game.

Australia also qualified from Group B while Switzerland was eliminated.

The Italians also secured qualification from Group A on Sunday Matteo Arnaldi and Lorenzo Sonego won their singles fixtures against the already-eliminated Sweden.

It took only one hour and 22 minutes for Arnaldi to seal the deal for the Italians, as he defeated Leo Borg 6-4, 6-3.

His compatriot Sonego delivered, cruising past Elias Ymer 6-4, 6-4.

They will be joined by defending champions Group A winners Canada to whom they lost in the semi-finals last year.

Canada sealed their fate after a 2-1 win over Chile on Saturday.

They only needed to win one of their three games against the South Americans and Alexis Galarneau made no mistake as he got the better of Alejandro Tabilo 6-3, 7-6.

The Chileans levelled the tie as Nicolás Jarry shocked Gabriel Diallo 6-4, 6-4.

Canada then won the tie in the doubles as Galarneau and Vasek Pospisil combined to beat Marcelo Tomás Barrios Vera and Tabilo.

Group C saw the Czech Republic and Serbia make it out for the knockouts.

Novak Djokovic, who won his 24th Grand Slam singles title at the US Open, continued his stellar from with a 6-3, 6-4 win over Spain's Alejandro Davidovich Fokina on Friday.

Earlier, Laslo Djere made it 1-0 as he defeated Albert Ramos-Vinolas 6-4, 6-4 while the doubles pair of Nikola Ćaćić and Miomir Kecmanović completed the rout with a 6-4, 7-6 triumph against Davidovich Fokina and Marcel Granollers.

The Czechs also instilled a 3-0 win over Spain and also shocked Serbia yesterday by the same scoreline to qualify as the top team from the group.