Acapulco - Nick Kyrgios continued his scintillating run at the Mexico Open on Friday, downing third-seeded John Isner in three sets to book a title showdown with world No 3 Alexander Zverev.

Australia's Kyrgios, the former world No 13 who has slipped to 72nd in the rankings, defeated Isner 7-5, 5-7, 7-6 (9/7), following victories over 17-time Grand Slam champion Rafael Nadal and three-time Grand Slam winner Stan Wawrinka.

Kyrgios, 23, reached his first ATP final since capturing his fourth trophy in Brisbane in January 2018.

Second-seeded German Zverev powered into his first final of the year with a 7-6 (7/0), 6-3 victory over Britain's Cameron Norrie.

Two nights after he saved three match points in a final-set tiebreaker against Nadal, Kyrgios converted his third match point with a drop shot from the baseline, sealing the win after two hours and 21 minutes.

He broke Isner in the penultimate game of the opening set, and Isner returned the favor late in the second. Neither mustered a break point in the third.

"I was just trying to take care of my serve, that's really all you can do against John," said Kyrgios, who had the edge on Isner in aces with 25 to the big-serving American's 24.

The unpredictable Australian, who seemed rattled at times by hostile fans in his victories over Nadal and Wawrinka, played happily to the crowd on Friday.

"It's insane," he said. "One point they were cheering my name, another point they were booing me. It's just entertainment."

Zverev, 21, is playing just his second tournament of the year after crashing out of the fourth round of the Australian Open.

He hasn't dropped a set all week, and was convincing against the 64th-ranked Norrie.

Unable to serve out the first set, Zverev raced through the tiebreaker and quickly seized a 3-0 lead in the second set, relying on a strong baseline game and 10 aces.

"It was very tough. It was pretty windy out here, not easy conditions, and his game actually I think fits the wind quite well, so it was not easy," Zverev said. "I'm just happy to be through." 

In women's semi-final action, China's Wang Yafan ousted third-seeded Croatian Donna Vekic 2-6, 6-3, 6-1 to reach her first WTA Tour final.

She'll face fifth-seeded American Sofia Kenin, who defeated Canadian Bianca Andreescu 6-4, 3-6, 7-5.

After dropping the first set Wang - 24 and ranked 65th in the world - squeaked through in a second set that featured just one hold of serve.

Although 28th-ranked Vekic converted all six of her break points against Wang, 39 unforced errors ultimately proved too much to overcome and Wang didn't face a break point in the final set.

Kenin will be looking for her second title of 2019, having broken through for her first WTA crown at Hobart in January.

Results from Mexico Open ATP and WTA tournaments in Acapulco on Friday (x denotes seed):