Just hours after Sifan Hassan of the Netherlands broke the world one-hour record on the track in Brussels, Peres Jepchirchir of Kenya broke the women-only world record for the half-marathon in Letná Park in Prague in the elite-only Prague 21.1 KM.  The petite athlete from Kapsabet clocked 1:05:34, smashing the ratified World Athletics record of 1:06:11 set by Netsanet Gudeta at the World Athletics Half-Marathon Championships in Valencia in March, 2018.

"I am so happy, happy," she said in her brief post-race television interview.  "I'm proud."

A field of seven women set out at sunrise on the specially-designed 16.5-lap course which had long straightaways and tight, teardrop turns at each end. Led by Kenyan pacemakers Brenda Jepleting and Lilian Jepkorir Chebii, the pace was aggressive from the start. Jepchirchir, dressed in black and white adidas kit, pushed up close to the pacers early on, anxious to run fast.

The 5-kilometer checkpoint was reached in about 15:23, well inside of world record schedule. The pace was already too hot for the pacemaker Chebii, and she fell well back. Jepleting led the all-Kenyan field of Jepchirchir, Edith Chelimo, Dorcas Jepchumba Kimeli, Vibian Chepkirui, and Sheila Chepkirui.

With a live drum ensemble accompanying the recorded music, Peres was feeling frisky. Just 20 minutes into the race, she left the field and forged ahead on her own. Her lead stretched to 10 meters in under a minute, and by the time she hit 10-K in a blistering 30:32 she was all alone.

"She must feel comfortable to take it on this early, to do it on her own," commented Dutchman Michel Boeting during the television broadcast.

Her long braids bobbing behind her, Jepchirchir was running each of the 1280-meter laps well under four minutes, a pace of about 3:03 per kilometer. She might have been running too fast.

"Let me tell you, that's fast," said Boeting.

Going into six laps (7680m) to go, Jepchirchir completed the previous circuit in 4:06, the slowest of the race. Her form wasn't as clean, her stride not as bouncy, as before. However, that was the pace she could hold, and it was good enough to bring her to the finish with the record.

"Yes, I am satisfied," she said. "Maybe I was thinking I was going to run 64:50."

The men's race played out similarly, but since it started later it was much hotter. Despite the heat, Kibiwott Kandie broke away from the field after 10-K, then ran alone to the finish in 58:37, making him the fifth-fastest man in history.

"Yes, I am satisfied with the time for today," he said in his post-race television interview. He added: "It was up to me to run alone."

Philemon Kiplimo Kimaiyo finished second and was the only other man to break the one-hour mark (59:56). Third place went to Benson Kipruto in 1:00:06.