Making his debut on 26 April 2018, aged 17, McDonald prevailed over three-time winner and former professional golfer Jason Palmer in an extremely close encounter, snatching the game on a crucial conundrum with both players already over 100 points. McDonald sealed another seven victories, all of which were centuries, including a top score of 121. His octotal is 882. His numbers, particularly, were very strong: of the 320 points available from these in his run, he accumulated a raw score of 308, placing him equal second (with Stephen Read) on highest cumulative score from 32 numbers rounds in an octorun, behind Dylan Taylor’s 311. He is the first ever octochamp born in the 21st century, having been born in January 2001.
As a result of his success in the heats, McDonald was invited back for the Series 78 finals as #2 seed. In his quarter-final, however, he finally suffered his first defeat against six-time winner and fellow Apterite Philip Aston after an unsolved and very difficult crucial conundrum eluded both players. However, even here, he scored an impressive 97 points, ensuring a joint score over 200 for this highly anticipated episode.
|#||Date||Type||Contestant 1||Score||Contestant 2||Guest||Lex||Max|
|6814||26/04/2018||P||Jason Palmer||104 – 115||Toby McDonald||Chris Packham||Susie Dent||135|
|6815||30/04/2018||P||Toby McDonald||108 – 68||Maxim Hall||Chris Packham||Susie Dent||123|
|6816||1/05/2018||P||Toby McDonald||121 – 32||Colin Beckwith||Chris Packham||Susie Dent||126|
|6817||2/05/2018||P||Toby McDonald||110 – 38||Terry Monaghan||Dr Phil Hammond||Susie Dent||134|
|6818||3/05/2018||P||Toby McDonald||111 – 10||Alyssa Critchley||Dr Phil Hammond||Susie Dent||125|
|6819||4/05/2018||P||Toby McDonald||109 – 53||Nilesh Pandya||Dr Phil Hammond||Susie Dent||124|
|6820||7/05/2018||P||Toby McDonald||104 – 71||Simon Cluskey||Dr Phil Hammond||Susie Dent||146|
|6821||8/05/2018||P||Toby McDonald||104 – 46||Lee Padovani||Dr Phil Hammond||Susie Dent||128|
|6848||15/06/2018||QF||Toby McDonald||97 – 104||Philip Aston||Helen Fospero||Susie Dent||123|