He first appeared in Series 41 in 1999 where he won his first game against Billy Davidson. He then won his second game against Julie Smithies before bowing out in a defeat to Rob Watson. Manwani returned to the programme 19 years later in 2018 during Series 79 and won all 8 heat games, becoming the second octochamp of the series, following Adam Rolston completing his run before Manwani.
As a result of his successes, he garnered a place in the series finals in December 2018 as number 5 seed. In his quarter-final match, he was on impressive form, maxing 11 rounds and achieving a personal best of 114 to outrun Dave Ashton. In his next game, he played against number one seed Martin May. Both players played a close run with May eventually running 10 points ahead, and when neither player solved the crucial conundrum, Manwani bowed out in a defeat.
|#||Date||Type||Contestant 1||Score||Contestant 2||Presenters||Guest||Lex||Max|
|2610||29/09/1999||P||Billy Davidson||47 – 54||Tony Manwani||Richard Whiteley||Carol Vorderman||Angela Rippon||Damian Eadie||72|
|2611||30/09/1999||P||Tony Manwani||56 – 43||Julie Smithies||Richard Whiteley||Carol Vorderman||Angela Rippon||Damian Eadie||74|
|2612||1/10/1999||P||Tony Manwani||28 – 44||Rob Watson||Richard Whiteley||Carol Vorderman||Richard Stilgoe||Susie Dent||72|
|6896||27/08/2018||P||Paul Beever||77 – 98||Tony Manwani||Nick Hewer||Rachel Riley||Raj Bisram||Susie Dent||136|
|6897||28/08/2018||P||Tony Manwani||105 – 58||Pamela Threlfal||Nick Hewer||Rachel Riley||Anne Hegerty||Susie Dent||136|
|6898||29/08/2018||P||Tony Manwani||99 – 62||Joe Sinclair||Nick Hewer||Rachel Riley||Anne Hegerty||Susie Dent||122|
|6899||30/08/2018||P||Tony Manwani||90 – 26||Chris Davidson||Nick Hewer||Rachel Riley||Anne Hegerty||Susie Dent||126|
|6900||31/08/2018||P||Tony Manwani||84 – 38||Nick Fisk||Nick Hewer||Rachel Riley||Anne Hegerty||Susie Dent||123|
|6901||3/09/2018||P||Tony Manwani||67 – 43||Tom Kistell||Nick Hewer||Rachel Riley||Anne Hegerty||Susie Dent||132|
|6902||4/09/2018||P||Tony Manwani||90 – 74||Sam Klineberg||Nick Hewer||Rachel Riley||Mark Pougatch||Susie Dent||121|
|6903||5/09/2018||P||Tony Manwani||82 – 73||Duncan Hill||Nick Hewer||Rachel Riley||Mark Pougatch||Susie Dent||120|
|6976||18/12/2018||QF||Dave Ashton||79 – 114||Tony Manwani||Nick Hewer||Rachel Riley||Phill Jupitus||Susie Dent||129|
|6977||19/12/2018||SF||Martin May||93 – 83||Tony Manwani||Nick Hewer||Rachel Riley||Phill Jupitus||Susie Dent||147|