Teenage sensation Alex de Minaur is the lowest-ranked Sydney International semi-finalist in almost 30 years and one win away from a maiden ATP tour final after pulling off yet another upset in front of his adoring home-town fans.
Australia's world No.167 fended off a powerful display from Feliciano Lopez on Thursday to prevail 6-4 6-4 and will play unseeded Frenchman Benoit Paire on Friday for a spot in his maiden ATP final.
Half the age of his accomplished opponent and former world No.12, de Minaur stood firm against Lopez's 200km-plus serves and executed his game plan of avoiding the Spaniard's ferocious forehand.
The physical lightweight also showed nerves of steel on consecutive service games when he fought back from 0-30 down to claim the first set and again at the start of the second.
The world No.36 could only watch as the teenage sensation proceeded to twice break serve in the second set to claim his fifth top-50 scalp of the summer.
He entered the match as the youngest Sydney quarter-finalist since mentor Lleyton Hewitt won the title in 2000 and delighted the Davis Cup captain watching on from the stands.
"How good is this? This is what you play for," de Minaur said after backing up his run to the semi-finals at last week's Brisbane International.
"I'm really proud of my effort today.
"It was definitely a big thing. I tried to return everything I could, just try to apply constant pressure on his serve. That way I could get myself in the point and try to dictate from there."
Earlier on Thursday, the 42nd-ranked Paire sent down 17 aces to stun defending champion Gilles Muller 6-4 6-4.
It is the second semi-final for Paire in less than a week, having also fallen short of a decider in India.
Fourth seed Fabio Fognini set up a semi-final against qualifier Daniil Medvedev following a 7-6 (7-4) 6-7 (7-4) 6-2 marathon against Adrian Mannarino.
Medvedev is eyeing off his first career title after toppling veteran Italian Paulo Lorenzi 6-3 6-3.
"I feel quite confident, but at the same time, I know that Fabio is amazing player," Medvedev said.
"I lost to him once last year. So it's going to be a tough battle, and I will try to be the winner."