In the third game of set two Tsitsipas was in real trouble at 0-40. But five rapid points in a row and the 2021 finalist found his spark.
The 23-year-old kept the Next Gen prodigy at bay and struck for an essential break at 5-3, Tsitsipas locked into ‘no miss mode,’ Rune’s striking was slightly too ambitious and they levelled up.
In set three the pendulum swung again at 3-2, Tsitsipas down 0-40 again, but this time he couldn’t escape. The teenager maintained his advantage, drawing almighty applause by claiming a 19-shot rally at 5-3 to crack the Tsitsipas resistance and edge a set away.
The statement ‘victory belongs to the most tenacious’ is stencilled onto the inside of the stands on Court Philippe-Chatrier and Rune personified that phrase.
The former junior world No.1 then cantered 5-2 up in the fourth set before some understandable nerves saw nine successive points head Tsitsipas’ way.
Serving out at the second attempt at 5-4, Rune sparked a final forehand winner, curtailing a three-hour exhibition of why this Dane is destined for the very top.