De Minaur, who was hoping to make it to his first Grand Slam semi-final at the seventh time of asking, had not beaten world number one Alcaraz in five previous attempts.
In a tight opening set, De Minaur thrilled the crowd with aggressive hitting as he tried to match the world number one’s speed and intensity.
He twice clawed his way back from a break down before the top seed struck the decisive blow at 6-5 after almost an hour on court.
Former Wimbledon winner Pat Cash said the first set showcased “some of the highest level tennis I’ve ever seen”.
“It was two players refusing to back down, they were hitting balls from two or three feet behind the baseline,” Cash told BBC Radio 5 Sports Extra.
“It was like a video game, pinging backwards and forwards. It was so quick; there were drop shots, defensive lobs, chase backs, there was everything. An unbelievable set of tennis.”
But the gap in quality soon became evident as Alcaraz raised his level and De Minaur struggled to land any punches on the six-time major winner’s serve.
“As soon as we started asking can he [De Minaur] keep the level up, the wheels fell off and Alcaraz didn’t retreat,” Cash added.