Swift took to the stage at 7.50 pm at Accor Stadium in Olympic Park in Sydney's west in a balmy 30C after the city sweltered in 36C heat for most of Friday afternoon.
Heavy rain and lightning just before 6pm forced parts of the arena to be temporarily evacuated and prompted the cancellation of support act Sabrina Carpenter.
But the bad weather passed in time for Swift's arrival on stage, slightly after the 7.30 scheduled start time.
Many "Swifties", some clad in sparkly official merchandise, had headed early to Olympic Park ahead of gates opening at 4.30pm for the Eras Tour.
Swifties arrived ahead of the gates opening at 4.30pm when the temperature was still in the mid-30s. (Dean Lewins/AAP PHOTOS)
Swift fan Sophia Nott, 19, said being stopped from entering the venue due to wet weather had not dampened spirits among her friends in the show's lead up.
"We're super excited, everyone's very excited, everyone's starting to exchange friendship bracelets," Ms Nott said.
The stadium holds 80,000, and by the time Swift finishes the Sydney leg of her global tour she would have played before 320,000 people.
Close to a third were coming from outside NSW, which is banking on an economic dividend of $80 million by the time Swift moves on.
Prime Minister Anthony Albanese was in the crowd on Friday night, after earlier in the day quipping he could be the least famous person there.
"I'm way down the list ... Sydney, just like Melbourne last week, has just gone cray cray for Tay Tay," Anthony Albanese told Sydney radio FoxFM.
Mr Albanese remained tight-lipped on whether he was up to making or wearing friendship bracelets popular amongst the fans but admitted he had been given some by avid Swifties.
"People keep giving me these bracelets, which is fantastic," he said.
Mr Albanese will be in the crowd despite Susan Ley's urging to 'give up his ticket to a real fan'. (Joel Carrett/AAP PHOTOS)
Transport for NSW said with Swift set to "electrify" the city, more than 1,200 additional trains and buses would run over the four days to get fans to and from the arena.
Ticket prices for the sold-out shows range from $79.90 for the cheap seats up to dance-floor tickets for $380 and $1249 for the top VIP packages.
Thousands of Swifties have already parted with their hard-earned cash at merchandise pop-ups in the past few days, when many queued for hours.
Swift, 34, landed in Sydney alongside her support act Sabrina Carpenter on Monday after playing three shows at the Melbourne Cricket Ground, which drew the biggest audience of the superstar's career.
She was spotted at Italian restaurant Pellegrino 2000 in Surry Hills with Carpenter on Tuesday night and at Sydney Zoo in western Sydney on Wednesday.
Taylor Swift took to the stage in Sydney after rain prompted fans to be temporarily evacuated. (Joel Carrett/AAP PHOTOS)
Her partner and NFL superstar Travis Kelce, also 34, arrived in Sydney on Thursday morning, sending fans into a frenzy, before attending Friday's concert.
Swift is expected to rake in about $27 million for each of her seven Australian shows and will personally pocket about $5 million per show.
The Eras Tour as a whole, beginning in March 2023 and due to finish in December, is already the best-selling concert tour ever and the first to surpass $1 billion in ticket sales.
7°C