Brazilian tightrope walker Rafael Bridi set a new record by walking more than 500 meters between two buildings, more than 100 meters above ground in Sao Paulo.
The 25-minute walk was a new distance record for urban areas in the Americas.
"I cannot even remember what I was thinking about," Bridi told AFP after his aerial exploit on Wednesday.
"I was concentrating very hard, especially on my breathing, an effort which comes from the stomach."
He also had to "maintain a relaxed posture so the crossing is a pleasure and not a huge effort."
The 35-year-old high-wire specialist walked 510 meters - about a third of a mile - along a slackline strung 114 meters (375 feet) above ground between two tall buildings in the Vale do Anhangabau neighborhood in central Sao Paulo.
There was one nervy moment around halfway across the slackline when Bridi slipped, but he sat down to regain his balance before standing up again a few seconds later and continuing his challenge.
The record-breaking attempt by a man already recognized by the Guinness Book of World Records, coincided with the 469th anniversary of Sao Paulo, the immense megapolis of 12 million people in southeastern Brazil.
"I feel very honored" and "very welcomed" by locals, said Bridi. "It's not just a crossing, it's a record for Sao Paulo's anniversary."
From his unique vantage point, Bridi said Sao Paulo was an impressive sight due to "such a mass of people."
"I looked down, I saw people in the buildings and waved to them," added Bridi.
"After all, men built these buildings so why not use them in another way."
Bridi, who is from the southern city of Florianopolis, is accustomed to spectacular death-defying feats.
In 2021 he walked between two hot air balloons more than 1,900 meters (6,230 feet) above ground, breaking another record.
In 2020, he pulled off a world's first by walking above an active volcano in Vanuatu.
He has been tackling such gravity-defying challenges for a decade.
"Every morning I wake up thinking of highline and at night I go to bed thinking of highline," he said.
His training routine is very strict.
"I wake up very early, I stretch, I meditate."
A sports fanatic, he is not solely dedicated to highline, though, training only three times a week on a slackline.
He also runs, surfs, cycles, goes canoing and rock climbing to "always keep this body moving."