Continuing to defy the hip flexor injury that threatened to end his season less than a week ago, de Minaur downed dual grand slam semi-finalist Karen Khachanov 6-3 6-4 to jump to seventh place in the Race to Turin's live standings.
Crucially, Australia's baseline warrior has leapfrogged Novak Djokovic and Frances Tiafoe, who have already been eliminated in China, as he chases more valuable rankings points in the quarter-finals - and potentially beyond.
But Alexander Zvererv, who will be the year-end world No.1, stands in his way after the German beat Alexander Bublik 7-6 (7-6) 4-6 7-6 (7-1).
In his fifth encounter against Khachanov, de Minaur knew efficiency was key.
"It was really important for me to serve well and I think I definitely did that, especially down the stretch," he said.
"I got into a little bit of trouble, a couple of love-30 games, and I was able to find some good serves when I needed it."
De Minaur, who reached the semi-finals at the prestigious season-ending tournament last year, cut a forlorn figure after being forced to retire early in the second set of last week's China Open final against Djokovic, when a set down.
His comeback has been nothing short of remarkable.
"Ultimately I've been getting better and better every day," the 27-year-old said.
"Today was by far my best match and I think that I'm only going to get better.
"I know that once I'm fit physically and mentally, I'm the player that I (want to be) and I'm excited to be competing and going to the tail end of these tournaments and feeling great about myself."
The Australian No.1 broke Khachanov in the eighth game of the first set, producing his trademark court coverage and nous before hammering a double-handed backhand down the line, bringing mentor and Davis Cup captain Lleyton Hewitt to his feet in the stands.
De Minaur then romped through the next game as he served for the first set, taking it with an ace when up 40-0.
He broke the 26th-seeded Russian to go up 2-1 in the second set and then again held to love.
De Minaur's brilliant groundstrokes and coverage continued as he went up 5-3, often drawing gasps and hearty applause from the crowd in Shanghai.
Khachanov dug in when he could and forced de Minaur to work hard to serve out the match, which he did after saving a break point.
The 27-year-old let out a roar after the straight-sets win as he marched into the last eight where a victory would vault him to within a win of rising to sixth in the Race to Turin standings.
Despite a 4-8 record against Zverev, de Minaur prevailed in their past two meetings, both at Laver Cup, including two weeks ago.
And Zverev has fitness problems of his own.
"My ankle was acting up, unfortunately," said Zverev, who saved three set points in the first-set tiebreaker.
"It was understandable because I have been playing a lot of tennis, which is kind of a good sign because I have been playing well. I am starting to feel my body more and more but I am happy to get through."
France's 56th-ranked Arthur Gea also reached the quarter-finals with an upset 7-6 (7-4) 6-4 win over 13th seed Jakub Mensik of Czechia.
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