Heather Watson struggled to hide her frustration after illness contributed to her defeat in the Australian Open first round.

The Guernsey-born player was provided with smelling salts during a medical time-out as she struggled during a 6-4 6-0 loss to Tsvetana Pironkova, and the British number one has admitted that she needs to discover the root of the problem after suffering similar issues in Melbourne two years ago.

After the match, the 22-year-old said: "On Monday, I woke up not feeling that great, just kind of bloated and weak and not that good, and I feel like that today. I just struggled on the court to have energy.

"I get this at different times. I have a day or two here and there where I feel like this. I'm going to see the doctor afterwards because I can't let this affect me any more. I've lost this week now."

Watson entered the tournament after winning her second WTA title in Hobart last week.