Daredevil Nik Wallenda wowed Chicago and the world with two skyscraper crossings on a tightrope without a safety net or a harness.

Thousands of cheering fans packed the streets around the city’s Marina City towers to watch the 35-year-old, heir to the Flying Wallendas’ family business, complete the back-to-back walks, including one wearing a blindfold.

As he stepped from the wire after completing the second leg, he tore off his blindfold and waved to the crowd, who erupted in cheers.

I love Chicago, and Chicago definitely loves me,” said Wallenda as he walked the wire, with the crowd of thousands below him screaming in support

The spectacle was telecast with a seconds-long delay on the Discovery Channel so producers could cut away if Wallenda fell.

It took him about six-and-a-half minutes to walk the 138-metre stretch at a 19-degree incline from the Marina City west tower to the top of a building on the other side of a river.

“I love Chicago, and Chicago definitely loves me,” said Wallenda as he walked the wire, with the crowd of thousands below him screaming in support. “What an amazing roar!”

The next stage of his high-wire event he undertook blindfolded – a 28m walk between the two Marina City towers, Chicago landmarks. He made the stretch in little more than a minute.

Residents of Marina City had been asked not to use laser pointers, camera flashes or drones that could interfere.

Two of his previous televised tightrope walks – over the brink of Niagara Falls in 2012 and across the Little Colorado River Gorge last year – drew about 13 million viewers each.

Hours before the tightrope walk, Scott Jensen waited to watch the spectacle with his 15-year-old son, Matthew.

“I think anybody who does something like this is crazy, and it’s a once-in-a-lifetime opportunity to see it,” Jensen said.

Spectators watching Wallenda making his tightrope walk uphill at a 15-degree angle. Photo: John Gress/Reuters

Journalists covering the event signed waivers relinquishing their right to claim emotional distress if they witnessed a catastrophe.

A year before Wallenda was born, his great-grandfather fell to his death during a tightrope stunt in Puerto Rico. He was 73.

“Life is on the wire,” Karl Wallenda once said.

“Everything else is just waiting.”