Heather Watson and Andy Murray
Watson and Murray continue their preparation for the Australian Open in Perth. Getty Images

Andy Murray continued his unbeaten start to the 2015 season after partnering Heather Watson to victory in Great Britain's Hopman Cup opener against France in Perth.

Murray, who won the World Tennis Championships in Abu Dhabi a few days ago, saw off Benoit Paire 6-2 7-5 in the opening rubber.

World number 20 Alize Cornet, who partnered Jo-Wilfried Tsonga to victory in last year's tournament, responded by defeating Watson 6-2 6-2 to set up a deciding doubles match.

Murray and Watson combined to prevail in three sets, taking the final set 10-8 to clinch GB's first win of the round robin stage.

The men's British number one had been struggling with a shoulder problem and said: "I had the problem in Abu Dhabi a couple of days ago and haven't had much time to serve after that.

"It doesn't really make sense for a right-handed player to have a problem with their left arm. So I am not sure exactly what it was and I had a scan in Abu Dhabi and that was all clear. But it's still a little bit sore today."

Team GB face Poland and Australia in their remaining round robin matches, with the top team from the two groups progressing into the final on Saturday 10 January.

The other winners on day one of the Australian Open warm-up included Czech Republic, Poland and United States, who were inspired by world number one Serena Williams.

Williams lost the first set 0-6 to Flavia Pennetta before winning the remaining two sets for the loss of just three games and the 18-time grand slam singles champion claims her performance picked up once she had a coffee.

"I'm so jet lagged and Flavia played really, really well and yeah, everyone needs coffee every now and then," said Williams.

"I am a coffee drinker. I didn't have mine this morning and I was just feeling it, so I just had to get some coffee into me.

"I just asked them to get me a shot of espresso. I asked them if it was legal, because I've never done it before."