Stan Wawrinka was briefly the fifth member of tennis' elite in the mid-2010s, so he's better placed than most to name which of the icons of the game was the most formidable ...

Sinner broke (or equalled) several records himself, such as joining Roger Federer, Novak Djokovic (twice), Ivan Lendl, and John McEnroe in winning three consecutive Grand Slam titles on hard courts.