Good to see that The Guardian considers (Mikhail) Tal to be an acceptable solution in an everyday crossword. World Chess Champion for only one year (1960-61) and scarcely a household name.
I'm with Brendan and Geeker in enjoying the current World Championship, a ding-dong battle indeed, with an extraordinary number of decisive games.
At least Nepomniachtchi as a solution comfortably fits the usual 15x15 grid, but of course The Times won't include him until he dies. I've looked up the longest words from his name: nonemphatic (dubious) and phonetician.