Smith first appeared on 23 November 2020 against six-time winner and usually dominant player in the form of previous Series 61 contestant Martyn Simpson. Smith proved to be Simpson's toughest opponent, beating him in the first numbers round to take the lead. However, Simpson risked POLEWARD in round 7 to take the lead by one point, and later extended his lead in round 11 before Smith clawed back in round 12. Smith finally unseated Simpson on a crucial conundrum to win his first game. Smith continued a very solid run of performances, including spots of nine-letter words such as ORIENTALS and COLOURIZE, solving six conundrums and achieving seven centuries. Smith wrapped up with a total of 869 points to place third in the seed table.
Twelve days after completing his octochamp run, Smith began his finals campaign against number six-ranked Phil Hulme in the third quarter-final match. Both players exchanged the lead frequently while remaining within the crucial 10-point margin in a very tense fight. However, Smith's victory was eventually confirmed by the end of the final numbers round by nabbing seven points in a six-small gamble from Hulme. Smith then took on number 2 seed Sam Cappleman-Lynes in the second semi-final. Both players found REFASHION in the first letters round. Sam took a convincing lead, but Smith beat him in three letters rounds spotting PARBOIL, TWOCKED and DOPAMINE. However, it wasn't enough as Sam broke away and won the game with 124 points as Smith bowed out in his first defeat with 83 points, and finished with an overall score of 1,043 points in his series run.
Smith participated in Championship of Champions XVI in January 2023, playing against Florence Cappleman-Lynes, the wife of Sam, in the year's first game. Smith would ultimately be defeated 100 – 69 by Florence, although he did produce a strong beater with TOREADOR.
|#||Date||Type||Contestant 1||Score||Contestant 2||Presenters||Guest||Lex||Max|
|7394||23/11/2020||P||Martyn Simpson||95 – 104||Leo Smith||Nick Hewer||Rachel Riley||Tim Rice||Susie Dent||138|
|7395||24/11/2020||P||Leo Smith||105 – 70||Jonnie Masterson||Nick Hewer||Rachel Riley||Tim Rice||Susie Dent||121|
|7396||25/11/2020||P||Leo Smith||126 – 40||Steve Whatmore||Nick Hewer||Rachel Riley||Samira Ahmed||Susie Dent||146|
|7397||26/11/2020||P||Leo Smith||114 – 81||Isabella Roper||Nick Hewer||Rachel Riley||Samira Ahmed||Susie Dent||134|
|7398||27/11/2020||P||Leo Smith||107 – 51||Amaar Iqbal||Nick Hewer||Rachel Riley||Samira Ahmed||Susie Dent||154|
|7399||30/11/2020||P||Leo Smith||102 – 61||Joe Timmins||Nick Hewer||Rachel Riley||Samira Ahmed||Susie Dent||124|
|7400||01/12/2020||P||Leo Smith||115 – 83||Liam Coles||Nick Hewer||Rachel Riley||Samira Ahmed||Susie Dent||124|
|7401||02/12/2020||P||Leo Smith||96 – 93||Nicola Newton||Nick Hewer||Rachel Riley||Nina Wadia||Susie Dent||125|
|7409||14/12/2020||QF||Leo Smith||91 – 80||Phil Hulme||Nick Hewer||Rachel Riley||John Inverdale||Susie Dent||123|
|7412||17/12/2020||SF||Sam Cappleman-Lynes||124 – 83||Leo Smith||Nick Hewer||Rachel Riley||Levi Roots||Susie Dent||157|
|7922||02/01/2023||CP||Florence Cappleman-Lynes||100 – 69||Leo Smith||Colin Murray||Rachel Riley||Richard Osman||Susie Dent||125|