Navratilova on Williams's form ahead of US Open final: 'She is moving as well as ever'

Navratilova added that she believes her technique is better than ever while of course the serve is also still there like always.

'She has been all business at Flushing Meadows this fortnight. Serena is looking fresh, sharp and healthy - there is a calmness about her here in New York which makes her the strong favourite to beat Bianca Andreescu, a Canadian teenager who will be playing in her first major final,' said Navratilova in her column on the WTA website.

'Without a doubt, Serena is playing at a higher level than she did at this summer's Wimbledon, where she was the runner-up to Simona Halep. '

'In my view, she is moving as well as ever. She might not be as fast as she once was, but her footwork, her technique, is better and she's still explosive,

'Cleaning up her technique - I can also really notice the improvement in her forehand - has helped to cut out the unforced errors. That serve has always been there - that's been the mainstay that she has built her game around,

'In my view, she is moving as well as ever. She might not be as fast as she once was, but her footwork, her technique, is better and she's still explosive.'

'Cleaning up her technique - I can also really notice the improvement in her forehand - has helped to cut out the unforced errors. That serve has always been there - that's been the mainstay that she has built her game around,' she added.