The United States made light of the absence of several top singles players as they began their Davis Cup Finals group stage campaign with victory over Chile on Wednesday.

Reilly Opelka and Brandon Nakashima both came through lengthy three-set battles to give their team a winning lead in the Group C opener in Zhuhai, China.

Olympic doubles silver-medallists Rajeev Ram and Austin Krajicek then beat Matias Soto and Tomas Barrios Vera to wrap up a 3-0 victory and join Germany at the top of the table.

Captain Bob Bryan was unable to call upon the likes of US Open runner-up Taylor Fritz, Frances Tiafoe or Tommy Paul but his team showed its strength in depth to win a tricky tie.

Opelka, ranked 309th in the world, beat 116th-ranked Cristian Garin 6-3, 4-6, 7-6(3) before Nakashima, the world number 40, beat Alejandro Tabilo 7-6 (7-5), 2-6, 7-6 (7-3).

Four groups of four nations are being contested in four different cities — Zhuhai, Bologna, Valencia and Manchester — with the top two from each group progressing to the final eight-nation knockout round in Malaga in November.

On Tuesday, Australia edged out France in the standout tie with Matthew Ebden and Max Purcell claiming the doubles decider in the Group B clash in Valencia.

Australia were given a flying start when Thanasi Kokkinakis battled to a 7-6 (7-4), 7-6 (7-3) win over the higher-ranked Arthur Fils, recovering a 2-4 deficit in the second set.

France responded with their number one Ugo Humbert dispatching Alexei Popyrin 6-3 6-2.

But Australia got the win as Ebden and Purcell teamed up to beat experienced French duo Pierre-Hugues Herbert and Edouard Roger-Vasselin 7-5, 5-7, 6-3.

Canada also began their quest well as singles wins for Denis Shapovalov and Felix Auger-Aliassime assured them of victory in their opening Group D tie against Argentina in Manchester.

Germany beat Slovakia in Group C. Belgium beat the Netherlands in Group A