Key Points

Despite a slow start, the 26-year-old World No. 204 showed remarkable resilience, fighting back against the physically struggling Dane and sealing the win in just under three hours.

The result not only earned him a spot in the semi-finals but also guaranteed his long-awaited debut inside the world's Top 100. With this win, Vacherot jumped 112 spots to No. 92 in the live ATP Rankings, becoming the second lowest-ranked semi-finalist in Masters 1000 history since 1990.

"I didn't come as a qualifier, I came as an alternate. I wasn't even sure I was going to play qualifying," Vacherot said after his victory. "This is just unbelievable. The last win meant already so much to me. This one means even more."

The breakthrough moment was full of emotion for the Monegasque, who admitted he tried to stay calm even as the thought of breaking into the Top 100 loomed large.

"It was tough not to think about it on match point, also breaking the Top 100," he said. "I know this is just a step, but I tried not to look at the rankings for this whole tournament. I had read that if I won, I would break the Top 100, but this is just unbelievable for me. I cannot wait for the semi-final. I'm just so happy and living the dream."

Rune, ranked No. 11 in the world, twice called for medical attention in the deciding set as he struggled with a leg issue, but Vacherot held firm under pressure. He saved two break points in the tenth game before converting his second match point to seal the biggest win of his career.

Vacherot's journey in Shanghai has been a story of grit and determination - he has come back from a set down in five of his seven matches so far, including two in qualifying.

Reflecting on his effort, he said, "First set, physically I was really shocked. That was a step above what I am used to. I already thought Tallon (Griekspoor, in the fourth round), tennis-wise was playing really good. Sascha Bublik, we know how he plays. You could expect any shot at any second. That's why he's so good. But today I was shocked by how (Rune) was defending. Points that I would win against 90 per cent of the guys, for him it was just a random ball."

He added, "I felt like I was coming in and would have an easy volley. So the first set was pretty physical. My lungs were screaming a little bit, but that helped me a lot for the second set, because I just went off to change and it helped me to play a little bit more free."

Already the first Monegasque quarter-finalist in Masters 1000 history, Vacherot extended his fairytale run by converting two of his four break points against Rune.

He will now face either Novak Djokovic or Zizou Bergs for a place in his maiden ATP final - a challenge that caps an extraordinary breakthrough week for the unheralded 26-year-old who, by his own admission, "wasn't even sure he'd play qualifying".

- IANS