Jennifer Aniston is as hot as ever at 51. Picture: Instagram

London - Posing revealingly in YSL hot pants and knee-high Givenchy boots, she seems keen to show there is only one Jennifer Aniston.

But the actress, who turned 51 on Tuesday, found that a former Friends co-star was trying to prove otherwise. Courteney Cox dressed in a long blonde wig and gold-rimmed aviator glasses, then posted a photograph on Instagram of her with Aniston.

Despite bearing an uncanny resemblance to her close friend, Cox, 55, captioned the image: "No matter how hard you might try... there’s only one Jennifer Aniston. Happy birthday my dear friend! I love you!"

Aniston showed off her age-defying looks for Interview magazine, posing in an array of designer wear that displayed her toned physique, including a black leather biker jacket and knee-high boots.

Jennifer Aniston poses for Interview magazine. Picture: Instagram

She was interviewed for the feature by actress Sandra Bullock, 55. During their chat the pair revealed they became friends after being introduced by actor Tate Donovan, whom both had dated in the 1990s.

Aniston suggested that, even though she is single, she still imagines becoming a mother.

"It’s not so much what I see myself doing, but it’s more like a little screenshot in my brain, where I hear the ocean, I see the ocean, I hear laughter, I see kids running, I hear ice in a glass..." she said.

Daily Mail