World number two Andy Murray, who was making his return to action following the birth of daughter Sophia last month, showed no loss of form after his absence by cruising past Taro Daniel.

The Australian Open runner-up comfortably won the opening set 6-1 and continued to press home the advantage by taking the second 6-3.

Daniel, ranked 85 places lower than Murray in the world rankings, proved unable to muster a response as he lost the final set 6-1.

Britain’s Dan Evans could not double his team’s advantage as the world number 157 was defeated by Kei Nishikori.

The Japanese player, ranked sixth in the world, was tested in the second and third sets of the match, but ultimately triumphed in straight sets 6-3, 7-5, 7-6.

Murray and Nishikori are due to clash in what could be a crucial singles match, with their tie following the doubles.

The United States are also level against Australia, with day one taking place in blisteringly hot conditions in Melbourne.

John Isner had put the American team into the lead, as they chase a first win against Australia since 1997, as he overcame Sam Groth 7-6, 6-2, 6-2.

Australia, though, were soon back level after Bernard Tomic secured a 7-6, 6-3, 3-6, 6-4 win over Jack Sock.

Elsewhere, world number one Novak Djokovic defeated Aleksandr Nedovyesov 6-1, 6-2, 6-3 in Belgrade, but it was only enough to put Serbia level at 1-1 with Kazakhstan.

However, Argentina are 2-0 up in their away tie in Poland, with Italy 2-0 up on Switzerland.

France lead Canada 2-0, with Germany and Czech Republic level at 1-1. 

Last year's runners-up Belgium are level 1-1 with Croatia.