Jack Sock of the US completed a clean sweep of his round robin singles matches with a 6-2, 6-2 straight sets win over Nick Kyrgios.

With the Americans already having earned their place in the fina on Saturday (January 7l, Sock played with a certain degree of freedom displaying some extrovert shots as he completed the win in 49 minutes.

Kyrgios, playing with his knee heavily strapped, had enjoyed an unbeaten singles run prior to today's match.

Sock gained the ascendancy early, gaining breaks of serve in the third and seventh game of the first set, while Kyrgios held serve only once in the second.

In the women's match, Australia's Daria Gavrilova levelled the tie with a 6-4, 4-6, 7-5 win over Coco Vandeweghe, sending the tie to the mixed doubles rubber.

The Americans, however, claimed victory overcoming a raucous atmosphere inside the Perth Arena, to win 4-1, 4-1 over Gavrilova and Matt Ebden, who replaced Kyrgios in the final match.

The doubles rubbers are being played in the Fast4 doubles format, where sets are determined on a first-to-four-games 

In the second match of today, Feliciano Lopez defeated Adam Pavlasek to help Spain claim a 2-1 win over the Czech Republic in the teams’ final ties of the tournament.

The Spaniard and young Czech, ranked 75th in the world, delivered some explosive rallies, much to the enjoyment of the crowd.

Unable to be separated, the first set went to a tie-break.

The 35-year-old Lopez required all of his experience to rally from 0-3 down in the tiebreak to close out the first set after his opponent hit a smash wide.

The second set remained on serve, with Lopez saving a break point early on.

Neither player looked troubled on serve until the ninth game of the set, where Lopez took the decisive break to serve for the match.

The Spaniard was untroubled, closing out the rubber 7-6, 6-4 to record his first win of the year.

Earlier, the Czech Republic had claimed a 1-0 lead in the tie after Lucie Hradecka defeated Lara Arruabarrena 6-2, 6-4 in the women’s singles rubber.

The tie, similarly to the first match of the day, was decided in the mixed doubles where Arruabarrena and Lopez claimed a 4-2, 4-1 victory over Hradecka and Pavlasek.

The penultimate day of the competition sees the conclusion of the group stage matches.

France take on Switzerland in the most important of the two matches, with the winner going on to face the US in the final.

Great Britain take on Germany in the other contest.