After storming through the first three rounds with the loss of eight games, Alex de Minaur had to do it the hard way against Holger Rune in the Acapulco semi-finals.

In a match that started on Friday night and carried on until nearly 3 a.m. Saturday morning, the Aussie outlasted his opponent in a 3-6, 7-5, 6-2 victory at the Abierto Mexicano Telcel presentado por HSBC. While Rune was electric in the early stages, he struggled physically in the final set as De Minaur’s staying power pushed him through the finish line after two hours and 48 minutes.

“It feels great. It feels like I deserved it,” the Aussie said after advancing to his 11th ATP Tour final, where he will face Tommy Paul. “I hung in there, I stayed tough.

“[I had to] stay with him. It’s not easy because he’s a hell of a player. He was hitting me off the court at times and not letting me really do much. But I managed to save a couple of crucial break points and keep giving myself chances… I took the one chance I [converted] and rolled with it.”

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Rune’s big hitting dominated the opening set, though the Dane still needed to fight off four break points to consolidate an early break and move 4-1 ahead. He closed the set in style with an aggressive net approach, the power play providing a fitting end to the stanza.

De Minaur began to sink his teeth into the match in set two, dragging Rune into longer rallies and winning the lion’s share of the extended exchanges. Despite plenty of break chances — six for De Minaur and four for Rune in the set — the decider was on the verge of a tie-break before the Aussie scored his first break to clinch the set, converting on his 10th break point of the match.

Rune began to struggle physically in the final set as the Acapulco humidity took its toll, and De Minaur took full advantage. While Rune fought through cramps and began hitting even bigger to shorten the points, De Minaur continued to move him around the court. A late surge from Rune was not enough to turn the tide as De Minaur progressed to his first final since he won the Atlanta title last July.

“I know I can go for a very long time so I’m happy with the work I do,” De Minaur said of his fitness level. “It just shows that I can do this for a while.”

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By beating the World No. 10, De Minaur earned his third Top 10 win of the season (also def. Nadal, Rublev) and his 10th overall. He also improved to 11-7 in tour-level semi-finals by earning his first win in three ATP Head2Head matchups with Rune.

The Dane, who was seeking his fifth final since late September, can take solace in the fact that his semi-final run moved him up two places to No 8 this week in the Pepperstone ATP Live Rankings. Guaranteed to maintain that position at week’s end, the 19-year-old will reach a new career-high on Monday in the Pepperstone ATP Rankings.

De Minaur is back into the Top 20 behind his final run after a rising three spots to No. 19 this week in the Pepperstone ATP Live Rankings. The winner of Saturday’s final between De Minaur and Paul will enter Indian Wells as the World No. 18.

“He’s playing some great tennis. Just look at his results here,” De Minaur said of the seventh-seeded American. “It’s going to be a great match. I’m looking forward to a battle and to just go out there and leave it all out there. There’s not much else you can do. Enjoy the moment.”