Move over Ash Barty – Australia has a new number one tennis champ.

Melbourne grandmother Shirley Whitaker, 85, is the new world’s number one tennis player in the 85-and-over age group.

Ms Whitaker scored the world No.1 ranking after winning the singles competitions in two ‘super seniors’ tournaments Poertschach, Austria this month.

After winning the Austrian Senior Championships earlier this June, she went on to win the 85-plus section of the European Senior Championships a week later.

Her two victories propelled her to the number one spot.

According to a Fairfax report, on Monday her longtime social-tennis pals at Doncaster Tennis Club asked her how she went in Europe, to which Ms Whitaker replied, "oh, not too badly", showing them her International Tennis Federation No.1 ranking on her iPad.

Suffice to say her friends were amazed.

But Ms Whitaker remains humble.

“I'm no star,” she said. “Just an old lady enjoying tennis who's surprised herself with her effort."

She’s played tennis for 75 years, nowadays playing twice a week. She rates herself a "good average" tennis player.

"Probably I move fairly well, which is an asset when you get older,” she said.

"I haven’t had any knee replacements, no hip replacements, no shoulder problems."

Mrs Whitaker is happy to be a No.1 player, but she has no plans to go on the seniors circuit.

"I'm not that driven, although I'm thrilled about what's happened. If I was 10 years younger, you'd think about it differently of course, but living so far away from where the action is, makes you think about it more."

She just wants to play with her mates.

How good is this? Do you know any other inspiring older sportspeople?