THERE was nothing ordinary about John Millman beating tennis’ greatest player of all time at the US Open on Tuesday.

His pre-game meal, however, certainly was.

On the morning of his career’s biggest match, the 29-year-old journeyman woke up, sipped on a flat white and ate some avocado on toast.

For lunch, he smashed a chipotle burrito.

Then in the evening, he smashed a 20-time grand slam champion off Arthur Ashe Stadium at Flushing Meadows.

Millman’s friend revealed to Triple M on Thursday morning that the giant-killer follows the coffee and burrito diet before every match.

Now Millman must face another tennis giant on Thursday to progress to the US Open semi-finals.

He faces 13-time grand slam champion Novak Djokovic on the same court he performed one of tennis’ all-time greatest upset victories.

The winner of the match will move on to face Kei Nishikori.