Protesters interrupted the U.S. Open.

But they couldn’t stop Coco Gauff and her inexorable march toward her first-ever Grand Slam title.

The American teen phenomenon ground out a 6-4, 7-5 semifinal victory over Karolina Muchova on Thursday night, a match delayed by almost 50 minutes due to a group of climate change protestors in the loge section of Arthur Ashe Stadium.

Four people got removed and given trespass notices.

One even glued his bare feet to the concrete floor, with security and law enforcement taking well over half an hour to figure out how to pry him away.

But on the court, Guaff’s feet were as fleet as ever.

The 19-year-old chased down ball after ball from Muchova, that athletic defense contributing to a 17 unforced errors in the first set by the 10th-seeded Czech.

Gauff broke Muchova’s very first service game, ran out to a 5-1 first-set lead and held on.

The second set was more of a grind, whether because of Muchova finding her game or Gauff losing hers amidst the lengthy delay.

The last hour was world championship tennis and Gauff came out on top.

After a first-round loss at Wimbledon, Gauff added renowned Brad Gilbert to her coaching team.

The results have been immediate and impressive, going 16-1 since with tourney wins at D.C. and Cincinnati, beating Muchova in the latter final.

Gauff did so again Thursday, moving into the final against the winner of the other semifinal between American Madison Keys and second-ranked Arnya Sabalenka.

Early in the second set with Gauff leading 6-4, 1-0, play got interrupted for 49:45 by what appeared to be a group of fans wearing “End Climate Change” shirts.

Four were removed and given trespass notices.

“We had environmental protestors up in the loge area. We had three, two were removed, quietly left,” tournament director Stacey Allaster told ESPN. “When security got there, they found one of the protesters had physically glued himself by his bare feet to the cement floor.

“There’s no doubt in a 24,000-seat stadium people get ideas. We know environmental protestors use the platform (of events like this).

“Certainly security will be resuming — along with law enforcement — to see what we can do to prevent it in the future.”

Meanwhile, Gauff is showing herself to be tennis’ future.

At 5-3, Muchova staved off a match point with a forehand winner, eventually pulling even at 5-all. But the teen held to stay on serve in the second.

A double fault handed Gauff a 15-0 lead, and she failed on four more match points. A staggering 40-shot rally gave Gauff her sixth match point, and fittingly clinched it on a backhand error.

The crowd erupted, Gauff cupped her hand to her ear and soaked up the applause.

The well-earned applause.