Williams has provided a huge surprise to snooker fans around the world with his latest revival in form.
The 43-year-old was considering retiring last year after his performances took a serious nose-dive.
However, his wife convinced him to continue and now the he has a shot at winning his third Championship.
Williams was part of the ‘big four’, along with Higgins, Ronnie O’Sullivan and Stephen Hendry, when he won the event in 2000 and 20003.
And 15 years on he has once again reach the showpiece finale in Sheffield – but how much is he worth?
How much is Mark Williams worth?
Williams has boosted his value quite substantially in 2018 and is said to have earned £3.4million throughout his 25-year career, according to snookerdatabase.co.uk.
The Welshman earned most of his money during the early part of his career.
His record winnings came in 2003 when he was awarded £270,000 for clinching the World Championship.
Williams could eclipse that figure this afternoon where he is guaranteed a minimum £180,000 for reaching this final – his biggest purse in 15 years.
An £80,000 reward was received for winning the German Masters in February.
However he could pocket the stunning £425,000 cheque if he beats Higgins in the World Championship final.
What has Mark Williams said ahead of the final?
Williams revealed earlier in the tournament that he would do his news conference naked if he won the trophy.
Asked if he will keep his word, Williams said: “Absolutely, no question about it. I will have nothing on at all.” He then picked up an ice bucket from the table and added: “I will hold this here.”
He added: “John is bound to have an advantage. It is nearly 1am and he is fast asleep in bed. It is only two more days and I can give it one last push.
“If I had to play him tonight, I would have nothing left in the tank and it would be 18-0 to him. I need a good night’s sleep and come out and the adrenaline should kick in to help me on the way.”