The hulking, seemingly unmanned golf cart was doing furious, breakneck doughnuts on the airport tarmac when a yellow-vested worker sprang into action.

What he did next won him applause from a terminal full of bleary-eyed travelers who had stopped to stare out the window at the bizarre battle royal playing out among rows of parked airplanes.

It eventually captured the attention of the president, too.

The dramatic scene unfolded Monday at Chicago’s O’Hare International, one of the country’s busiest airports, and footage of the episode rocketed across social media.

Hours after Kevin Klauer, chief executive of the American Osteopathic Association, posted the video to Twitter, it had racked up more than 7 million views. The worker in the vest was dubbed a savior.

What actually happened remains unclear. Karen Pride, the Chicago Department of Aviation’s spokeswoman, referred questions about the incident to American Airlines, which owns the equipment and employs the workers involved.

The airline’s media relations department emailed a statement that said the company is “investigating an incident involving a catering truck.”

“Preliminary reports indicate that the accelerator became stuck and caused the catering cart to lose control,” the statement continued. “No American Airlines team members were injured and the incident resulted in one 10 minute flight delay.”

One more thing is obvious: Were it not for one fast-acting employee, the runaway oversized cart may have hurtled into a plane parked at a gate.

As the vehicle spun wildly, apparently knocking one worker to the ground, others dodged and ran for cover. Some stood and looked around, seemingly unsure of what to do. The cart swerved and its wheels smashed what appeared to be soda cans, sending their contents spraying.

In the terminal, passengers gasped.

“Did she get hit?!”

“Oh my God.”

“What is going on?”

One worker scampered off-screen, narrowly avoiding a broadside from one of the cart’s swinging metal doors.

“Gonna hit the airplane — here it goes,” one spectator said.

Not so fast.

From stage right, the yellow-vested worker reappears in the video, at the helm of another airport ground support vehicle. Just in time, the worker dutifully rams the side of the wayward cart, toppling it over and sending its contents spilling over the tarmac — but sparing the airplane and co-workers.

Again, a chorus from the terminal.

“Oh, nice.”

“There ya go!”

“That’s how you do it!”

The crowd clapped its approval.

In its statement, American Airlines added, “We appreciate the quick action of our team member who stopped the vehicle.”

The morning after, President Donald Trump shared the video and praised the hero worker, tweeting, “Great job, just in time!”

The plane enthusiast website NYCAviation tweeted the understated shout-out, “Creative solution to a rather unusual problem.” And the website Deadspin awarded the clip its “Sports Highlight of the Day.”

One commenter summed it up simply: “We all need heroes.”