Ethiopia's Addisu Gobena and Kenyan world champion Peres surged to commanding wins Sunday in the men's and women's races respectively at the Sydney Marathon.
Victory was the first in a World Marathon Major for 21-year-old Gobena, who came second last year, while Jepchirchir added to her previous triumphs in Boston, New York and London.
Gobena made his move in the last kilometre to power home four seconds clear of compatriot Chimdessa Debele Gudeta in 2hrs 04min 42sec. Lesotho's Tebello Ramakongoana came third.
The dominant run shattered the course record by almost one-and-half minutes, with last year's winner Hailemaryam Kiros dropping from the pace in the dying stages.
"I am very happy," said Gobena, who was a javelin thrower before transitioning to long-distance running, gaining international attention by winning the 2024 Dubai Marathon.
"Last year I came second, I learnt from my mistake, and I went back home and I worked on my mistake to perform and break the record today."
The unstoppable Jepchirchir was in a league of her own, crossing the finish line in front of the Sydney Opera House in 2:18:31, nearly four minutes ahead of fellow Kenyan Irine Cheptai and Ethiopia's Shure Demise Ware.
"I was prepared, but I was not sure when I came here if I would win, so I'm so glad and I'm so happy," said Jepchirchir.
"It was so hilly. First half (of the race) was so tough, but the second was better at least. But it was not easy."
In the men's race, the leading pack had thinned to 15 by the halfway mark, with Gobena, world champion Alphonce Simbu and Kiros among them.
Dawit Wolde, Vincent Ngetich and Gobena all attempted breakaways, but they were reeled in by a pack reduced to seven with six kilometres left.
It was still the same group at the 40 kilometre mark before Gobena and Gudeta made their move, pulling clear with Gobena outkicking his countryman in the final sprint.
Kenya's Priscah Cherono went out hard among the women, opening a 20-second gap by 15 kilometres and 30 seconds by halfway.
But the lead chasers, down to just Jepchirchir and Cheptai, caught the 46-year-old Kenyan just before 30 kilometres.
Jepchirchir and Cheptai eased clear and the relentless world champion then put her foot to the floor, finishing nine seconds off the course record set by Olympic champion Sifan Hassan in 2025.
American Daniel Romanchuk won the men's wheelchair race, while Switzerland's Manuela Schar, a three-time Paralympic gold medal winner, took out the women's.
Around 40 000 runners, a record, competed over the picturesque 42.19 kilometre course through the city from North Sydney, over the Harbour Bridge to the finish line on the forecourt of the Opera House.
The race was elevated last year to the seventh World Marathon Major, putting it on a par with London, Tokyo, Boston, Berlin, Chicago and New York in the elite global series.