Casper Ruud became the first Norwegian man to reach a Grand Slam final on Friday when he set up a French Open title clash with 13-time champion Rafael Nadal, the man he described as his "idol".

World number eight Ruud defeated Croatia's Marin Cilic 3-6, 6-4, 6-2, 6-2 in a semi-final which was held up when a protester ran onto the court and tied herself by the neck to the net.

She wore a shirt which bore the slogan: "We have 1028 days left" before being eventually cut free by security staff. The match resumed after a 15-minute delay.

Ruud fired 16 aces and 41 winners past 2014 US Open champion Cilic.

"It was a great match from my side, I didn't start the greatest but Marin played a very good first set," said the 23-year-old Norwegian.

"I look up to Rafa. He's the perfect example of how to behave on the court, never gives up and never complains. He's been my idol all my life.

"He's the last player of the Big Three that I've never played against, so I guess this is perfect timing. To play him in a Grand Slam final will be great. Hopefully for him too, to be playing against a student from his academy."

Earlier Friday, Nadal reached the final in Paris for the 14th time when Alexander Zverev was forced to retire with an ankle injury after falling in the court.

Nadal was 7-6 (10/8), 6-6 ahead when the 25-year-old world number three quit.

Nadal, who turned 36 on Friday, will be playing in his 30th Grand Slam final and aims to become the oldest men's champion at Roland Garros and capture a record-extending 22nd major title.