The 18-time Grand Slam champion was locked in a fierce battle with Kyrgios, where all three sets went to a tie-break, and eventually emerged from a gruelling encounter with a 7-6, 6-7, 7-6 win after three hours and 10 minutes.

The 35-year-old will now take on arch-rival Nadal for the 37th time after he extended his impressive record in 2017 to 18 wins and one defeat.

It will mark the second meeting in a final between the two players after they met in the showpiece match at January's Australian Open, won in five sets by Federer.

"It felt very good," said the Swiss.

"You don't very often play three breakers in a match.

"Winning breakers is always such a thrill. 

"I tried to really fight for it. 

"I can't always show my fighting skills, it is great winning this way."

Kyrgios felt he put in a "good performance" during the epic tussle with Federer in front of a crowd who were largely cheering on the Swiss maestro.

"I had some ups and downs, bit of a rollercoaster," the Australian said.

"I thought the crowd would've enjoyed watching it, people at home would've enjoyed watching it. 

"But I wouldn't be surprised if they found something bad, though."

Spaniard Nadal enjoyed a much more comfortable outing on court as he swept aside Italy's Fabio Fognini, the first unseeded player to reach the last four in Miami for 10 years.

The 30-year-old breezed to the opening set and eventually wrapped up a commanding 6-1, 7-5 success.

The Miami Open continues tomorrow with the women's final between Britain's Johanna Konta and Denmark's Caroline Wozniacki.