Allan Simmons secured his place in the final with the word "naperies", Scots for table napkins.
Mr Simmons, from Coldingham Village in the Scottish Borders, beat 57 other Scrabble professionals at the semi-final in Cardiff at the weekend.
He will now go head-to-head with Paul Allan, who was crowned champion in 2007, in the National Scrabble Championship final in London on Sunday, November 3. The final will consist of a gruelling five-game showdown in front of an audience of Scrabble players.
Mr Simmons, a Scrabble consultant who previously won the championship title in 2008, said: "I am thrilled to have made it to the National Scrabble Championship final again, especially given the ever-increasing number of top-quality players competing.
"I will have to do some serious revising of my scrabble vocabulary to ensure I am on form to match the other finalist, and given that the grand final is played to a public audience of players who expect to be impressed."
Mr Simmons, who compiles puzzles for the media and puts together the page-a-day calendar in his role as Scrabble consultant, began playing the word game via the Postal Scrabble Club at the age of 16, before he joined the London Scrabble League.
The Scot, who also enjoys DIY, playing bass and walking his three flatcoat retrievers, has competed at major tournaments for 30 years.
The National Scrabble Championship semi-final was held at the Millennium Stadium in Cardiff, in conjunction with the Cardiff Mind Sports Festival.