Conner Mantz made history on Sunday morning as he smashed a more than two-decade-old American Marathon Record with his 2:04:43 finish at the 2025 Chicago Marathon.

Mantz capitalized on near-perfect race conditions and traversed the 26.2 mile course with near even splits throughout the race. He split 1:02:19 through the opening half marathon and only slowed by five seconds over the latter half. Mantz crossed the line in 2:04:43 for a fourth place finish. The previous American Record of 2:05:38 was set by Khalid Kannouchi in 2002.

• Subscribe to FloTrack Today
• Matthew Centrowitz Takes On Chicago Marathon in First Post-Track Effort
• Conner Mantz's Long Run During 2025 Chicago Marathon Build
• 2025 Chicago Marathon Live Updates.

Entering today, Mantz owned a personal best of 2:05:08* from the 2025 Boston Marathon earlier this year. That run, was not eligible for an American record because of Boston's downhill elevation loss from start-to-finish. The start line is also more than 50% of the race distance from the finish line.

Nevertheless, that run proved that Mantz was capable of an American Record run in Chicago. He purposely withheld himself from racing at the 2025 World Championships to prepare for the Windy City. Ultimately that decision paid off as he became the first American in history to break 2:05 on a record-legal course.

He also captured the North American Record with today's result. He now has two of the three fastest all-condition marathons in American History. Ryan Hall's 2:04:58 Boston Marathon American Record from 2011 moves to number two on the list.

The race was otherwise dominated by Ugandan Jacob Kiplimo. He rightfully scared the world record - before the wheels started to fall off around mile 20. He managed to hand on for the win in 2:02:23.

Behind Mantz, fellow North American Rory Linkletter put in a valiant effort for a ninth place finish in 2:06:49. He joked with Mantz earlier in the weekend about the prospects and respective race for the North American Record. Ultimately the American was triumphant over the Canadian in that escapade.

2025 Chicago Marathon Top Ten Men's Results

1. Jacob Kiplimo (UGA) 02:02:23
2. Amos Kipruto (KEN) 02:03:54
3. Alex Masai (KEN) 02:04:37
4. Conner Mantz (USA) 02:04:43
5. Huseydin Mohamed Esa (ETH) 02:04:50
6. Seifu Tura (ETH) 02:05:17
7. Geoffrey Kamworor (KEN) 02:05:31
8. Philemon Kiplimo Kimaiyo (KEN) 02:06:14
9. Rory Linkletter (CAN) 02:06:49
10.  Bashir Abdi (BEL) 02:07:08
11. Zouhair Talbi (MAR) 02:07:27
12. Timothy Kiplagat (KEN) 02:07:42
13. Daniel Ebenyo (KEN) 02:07:52
14.  Wesley Kiptoo (USA) 02:09:02
15. Ryan Ford (USA) 02:09:37
16. Galen Rupp (USA) 02:09:41
17. Andrew Colley (USA) 02:09:43
18. Aidan Troutner (USA) 02:10:23
19. Cj Albertson (USA) 02:10:38
20. Colin Mickow (USA) 02:11:24

Information About Entries At The Chicago Marathon 

• More than 50,000 runners are expected to take part in the 2025 Chicago Marathon. Over 160,000 applications were received for the race.

Chicago Marathon 2025 Schedule

• Elite men's wheelchair race: 8:20 a.m. ET
• Elite women's wheelchair race: 8:21 a.m. ET
• Elite races (men's and women's): 8:30 a.m. ET
• Last mass race wave: 9:35 a.m. ET

FloTrack Is The Streaming Home For Many Track And Field Meets Each Year

Don’t miss all the track and field season action streaming on FloTrack. Check out the FloTrack schedule for more events.

FloTrack Archived Footage

Video footage from each event will be archived and stored in a video library for FloTrack subscribers to watch for the duration of their subscriptions.

Join The Track & Field Conversation On Social

• Follow us on Twitter @FloTrack
• Follow us on Instagram @flotrack
• Follow us on TikTok @flotracktv
• Watch us on YouTube
• Like us on Facebook