A forensic accountant is the first woman to become Countdown champion in 26 years.
The long-running numbers and words game show, which has been on Channel 4 since 1982 when the broadcaster launched, has not had a female champion since 1998.
The match between Fiona Wood, from Kinross, Scotland and Chris Kirby went right down to the wire, but the accountant prevailed by getting the final conundrum: lassitude, meaning a state of physical or mental weariness.
The 50-year-old said: “I decided to apply after (host) Colin (Murray) appealed for older contestants with (lexicographer) Susie (Dent) adding that they wanted more women.
“I have absolutely no regrets about applying and would encourage other women to give it a go.”
“Fiona delighted us all and gave us one of the very best moments in our 42-year history,” Dent, who has appeared in the “dictionary corner” since 1992, said.
“This series also reminded us how much Countdown is a show for everyone, and we would encourage anyone who loves the game to apply via countdown@channel4.com.”
During the episode, Mr Kirby was let down when when he tried to get an eight-letter word score with “promotee”, over Ms Wood’s “promote”, but was told that the result was not in the dictionary.
Mr Kirby came back by succeeding in another words round with “routeing”, and they both were unable to manage adding up the right amount during the numbers section, and were shown the correct answer by Riley.
They continued to match each other, even getting the same word “opiates” during the tense 90th series final.
At the end, Ms Wood’s score was 96 to Mr Kirby’s runner-up score of 89.
After being presented with the trophy, she said: “I just can’t believe it. I’m not known for being decisive, and I thought long and hard before I decided to apply, and I’m just so glad that I did.”
The guest in the studio was actor and 2007 I’m A Celebrity…Get Me Out of Here! winner Christopher Biggins, who called the finale “magical”.
Last year, Northern Irish TV presenter Murray was named the permanent host of Countdown, taking over from former The Weakest Link host Anne Robinson.
Adapted from the French TV series Des Chiffres Et Des Lettres (Numbers and Letters), Countdown was originally hosted by Richard Whiteley.
Nick Hewer, Des Lynam, Des O’Connor and Jeff Stelling have also served as presenters.
Countdown is on Channel 4 from Monday to Friday at 2.10pm.