By Ian Laybourn, PA Sport

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Venus Williams will pass the world number one ranking on to younger sister Serena on Monday.

And there is the distinct possibility that by then the Wimbledon crown will also have changed hands, although strictly within the most famous tennis family in the world.

The Williams sisters share most things - they are currently living together in a rented house in Wimbledon - and are also in the process of dividing up the Grand Slam titles.

Venus beat her sister to win the US Open last September but Serena, who missed the Australian Open with an ankle injury, gained her revenge in the French final at Roland Garros last month.

The Williams phenomenon moves on to the All England Club on Saturday when the daughters of Richard and Oracene become the first siblings to contest the Wimbledon title since Harrow-born Maud Watson beat Lillian in 1884.

Although Venus goes into the final as top seed and defending champion and has won five of their eight previous meetings, Serena has secured enough points to displace her at the head of the world rankings, which officially change on Monday.

The sisters were hot favourites to contest a third Grand Slam in nine months and the odds are that Saturday's final will be one of the most closely-contested encounters of the championships, which have featured a series of predictable lop-sided matches.

The Williams have taken the women's game to a different level in the past fortnight and few of their rivals have been able to cope with the ferocity of their bludgeoning serves and flashing forehands.

Venus had a hiccup in the first set of her third-round match against Canada's Maureen Drake but she blitzed last year's beaten finalist Justine Henin in the semi-finals and she has spent less than six hours on court in the fortnight.

Apart from a tricky hurdle against Els Callens on the notorious Court Two, Serena has been just as dominant and, if she maintains her consistency, she could become the first player to win the title without dropping a set since Lindsay Davenport in 1999.

Venus, aiming to emulate Steffi Graf and Martina Navratilova by winning three Wimbledon titles in a row, has been impressed with his sister's form - they watch each other alongside mother Oracene at every opportunity - and accepts that she could be looking into a mirror.

"She's a great competitor," said Venus. "She has a big serve, has lots of power and a great forehand.

"She has lots of movement and just an all-round game. She can do anything. She has a game pretty much similar to mine so I respect that and I know where she's coming from."

Both girls have a burning desire to succeed but their encouragement for each other has inevitably raised suspicions over their motivation levels for matches between them.

The sisters, who are practice and doubles partners, have been unable to completely dispel the rumours of match-rigging by father Richard, even though he has stayed behind in Florida, and they were severely criticised for a low-key final in Paris.

But they insist they harbour individual ambitions and are able to cast aside family ties when it comes to the crunch.

"Just because I'm number one, it doesn't mean that I don't want to win Wimbledon," said Serena. "I'm really focused on playing Venus."

Serena was particularly awesome in her 6-2 6-1 semi-final victory over Amelie Mauresmo which was all over in 55 minutes and she is looking to pick up from where she left off.

"I have to play pretty close to the way I did yesterday to come close to beating Venus," she said.

"It's going to be quick because we both have big serves. I haven't lost serve in three matches so I'm really happy."