Breaking Update: 23-year-old Kelvin Kiptum broke the marathon world record in Chicago with a time of 2:00:35 on Sunday! Sifan Hassan defeated Ruth Chepngetich by almost 2 minutes and set a course record in the process, falling just short of the women's world record. 

The 2023 Chicago Marathon represented one of the deepest fields in its 45-year history. Kenyan phenom Kelvin Kiptum headlined the men's field, while Ruth Chepngetich set out to defend her title on the women's side. Both athletes are two of the fastest marathon runners in history.

2023 Chicago Marathon records

Kelvin Kiptum is now the fastest marathon runner of all time after entering as the second-fastest. At the 2023 London Marathon, Kiptum ran a blistering time of 2 hours, 1 minute, and 25 seconds (2:01:25). While he set a new record in Chicago, Kiptum had admitted his training was a little rocky.

“I think I have trained good. It was a little less [training], but I'm fit for the race,” Kiptum explained via LetsRun.com.

Eliud Kipchoge previously held the world record, but now Kiptum holds the title after nearly finishing in under 2 hours.

Americans Conner Mantz, Clayton Young, and Galen Rupp all performed well. Rupp is the only American male to win the Chicago Marathon within the last 20 years (2017 champion), while Mantz had the second-fastest American marathon debut in 2:08:16 at the 2022 Chicago Marathon.

This year, Mantz finished best among the American male competitors with a new PR of 2:07:47, which put him under the 2024 Paris Olympics qualifying time of 2:08:10. Young also qualified with a time of 2:08:00. Rupp didn't hit that qualifying time but still did well with a time of 2:08:48 as he made his return to racing.

On the women's side, Ruth Chepngetich was looking to defend her title and entered holding the third-fastest women's marathon time in history (2:14:18). Her personal best would be the second-best if not for Tigst Assefa's trailblazing world record in Berlin.

However, Sifan Hassan took home the title this time around, setting a new course record and moving to No. 2 all-time with a time of 2:13:44. Chepnegetich wanted to run the first half of the marathon in 66 minutes or faster and did that, but she fell behind as Hassan pulled ahead and wound up in second at 2:15:37.