The 20-year-old has validated his status as top seed, pushing through to Sunday's Brisbane International final with another tough victory, 6-4 7-6 (7-0), against Roman Safiullin.
He'll meet 2017 Brisbane champion and second seed Dimitrov, the Bulgarian fending off Australian Jordan Thompson in a tight 6-3 7-5 result later on Saturday.
Danish world No.8 Rune was tested by the in-form Russian, who had slipped under the radar on his way into the final four.
Broken early in the second set by the world No.39, Rune smashed his racquet in frustration but then regrouped to break back.
He then saved break points again before executing a faultless tiebreak.
Rune turns 21 in April but has already been as high as No.4 in the world, won nearly $US8 million ($A12 million) in prize money and made no secret of his ambitions.
Jordan Thompson couldn't repeat his heroics against Rafael Nadal as he lost to Grigor Dimitrov. (Jono Searle/AAP PHOTOS)
Rune dropped sets in both his first and second-round wins before winning tiebreaks in straight-sets wins in the quarter and semi-finals.
"It's exactly how I wanted it to be, to get the most amount of matches as possible," he said of his testing run to the final.
"It's a great challenge tomorrow to try to see where I'm at when it really matters.
"If I want to do what I want to do in Melbourne, I'm going to be under a much bigger amount of pressure if I'm going to stay on the last day on Sunday (in the Australian Open final).
"Tomorrow's a great challenge to see how I handle everything."
Thompson had beaten Rafael Nadal on Friday night, saving three match points in a clash that went into a fourth hour and finished at midnight.
He didn't roll over on Saturday though, forcing Dimitrov into some brilliant stroke play to twice hold serve and then break in the second set to make a third Brisbane final.
The world No.14 Dimitrov, who hasn't won a tournament since 2017 when he rose to No.3 in the world, whipped a forehand winner to create three break points then flicked a trademark one-handed backhand pass to break on the third attempt.
Dimitrov unleashes a backhand on his way to victory over Thompson. (Jono Searle/AAP PHOTOS)
"It continues; I love starting out here, the court feels like such a homely place," the 32-year-old said.
"It feels like coming into your living room and it's been a tremendous couple of weeks here.
"A very humble moment for me."
Rune and Dimitrov played twice last year, the pair splitting the meetings 1-1.
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