The duo ended Australia’s 17-year wait for a Hopman Cup victory last year after they brushed aside Ukraine in the final.

However, they got the defence of the title off to the worst possible start as they lost to Spain's Feliciano Lopez and Lara Arruabarrena by two rubbers to one.

Kyrgios flew out of the blocks, downing Lopez in straight sets 6-3, 6-4, powering down 14 aces and racing through the first set in just 23 minutes.

Gavrilova, the world number 25, meanwhile, was out of sorts against Arruabarrena, committing a significant number of unforced errors in both the singles and doubles matches.

Spain levelled the tie at 1-1 when Arruabarrena notched a 7-5, 6-1 win.

The Spaniards then prevailed in the Fast4 doubles format, where sets are determined on a first-to-four-games basis, winning 4-0, 4-2 to secure the tie 2-1.

In the second match taking place on the opening day, the United States claimed a comfortable 2-0 win over the Czech Republic.

Coco Vandeweghe beat Lucie Hradecka 6-4, 6-2 in the women’s singles before world number 23 Jack Sock claimed a 7-5, 3-6, 6-3 victory over Adam Pavlasek.

Action continues tomorrow where the second group of the competition begins.

The French team of Kristina Mladenovic and Richard Gasquet meet Germany's Andrea Petkovic and Alexander Zverev in the first match of the day.

Later on the Swiss team of Roger Federer and Belinda Benic take on Great Britain's Dan Evans and Heather Watson.

The tournament sees one male and one female player compete for their nation.

In total, eight nations will be represented at the tournament.

Split into two groups of four, each team plays the other three teams in their group.

The top placed team from each group at the completion of the group matches then meet in the final.