At the US Open in September 2021, Emma became the first player, male or female, to ever progress through qualifying stages en route to the title.
Former Wimbledon champ John followed a similar path, when, in 1977, he came through qualifying as an 18-year-old to reach the Wimbledon semi-finals.
The following year, he crashed out of Wimbledon in the first round.
Speaking to Radio Times, McEnroe said: “Expectations go up greatly when you pull off something like that [winning a grand slam], and Emma did something no one in the history of tennis has done.”