Alexander Zverev booked his place in a grand slam quarter-final for the first time after a third consecutive five-set thriller at the French Open.
The world number three, as in the second and third rounds, came back from the brink to defeat Karen Khachanov 4-6 7-6 (7-4) 2-6 6-3 6-3 on Court Suzanne-Lenglen.
The Russian claimed the third set with ease to seemingly send Zverev towards the exit door once more, but the nature of his recovery made this a deserved triumph.
Zverev may well be punished if he turns in similarly erratic displays against better players - Dominic Thiem is up next - but, for now, he will celebrate breaking new ground in a major.
The second seed is the youngest player remaining in the draw and the youngest to reach the last eight at Roland Garros since Juan Martin del Potro in 2008.
Early unforced errors saw the pair trade breaks, but it was not until late in the opening set, in sweltering conditions, that the match really started to hot up.
Khachanov held firm as Zverev pushed hard in a ninth game that proved pivotal when the German subsequently rescued two set points on serve but not a third, finding the net to hand his opponent the lead.
Another long slog was already on the cards for Zverev and he initially failed to serve out the second after breaking to get in front, fighting back from 0-40 down but then missing three opportunities to draw level in the match.
An ace in the tie-break did get the 21-year-old on the board, but his hard work was undone by successive breaks in the third after a double fault, allowing Khachanov to breeze back into the ascendancy.
Again Zverev came roaring back, though, and soon after being warned for court-side coaching and showing his frustration, he broke through to take control of the fourth.
And having capitalised on that advantage, another break followed in the first game of the final set when a sublime return forced Khachanov to play into the net.
Zverev then finally served up some consistency and ended on another break to continue this improbable streak of entertaining encounters.
Zverev  bt Khachanov 4-6 7-6 (7-4) 2-6 6-3 6-3
Zverev – 63/51
Khachanov – 45/51
Zverev – 17/4
Khachanov – 9/4
BREAK POINTS WON
Zverev – 5/13
Khachanov – 5/17
FIRST SERVE PERCENTAGE
Zverev – 67
Khachanov – 64
PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Zverev – 73/48
Khachanov – 65/57
Zverev – 156
Khachanov – 146