SAN FRANCISCO — CJ Albertson bettered the men's world record* in the 50km run Sunday at the Ruth Anderson Memorial Endurance Run, clocking 2:38:43 on a course that circled Lake Merced Park. Albertson's time was 1:30 faster than the pending world record of 2:40:13 that was run by South Africa's Stephen Mokoka in March, and was 3:24 better than the ratified WR of 2:42:07, set last year by Ketema Negasa of Ethiopia. The existing American record for 50km is 2:43:45 by Josh Cox in 2011. Albertson was seventh at the 2020 U.S. Olympic Trials marathon in Atlanta and set his marathon personal best of 2:11:18 later that year in Chandler, Arizona. He finished 13th at this year's Boston Marathon in April after a 10th-place effort in 2021, running 2:10:23 on the Boston course that is ineligible for record purposes. On the track in 2020, Albertson ran 2:42:30 for 50km, faster than the previous world best of 2:43:38, and he also has an indoor marathon PB of 2:17:59, set in 2019. *Pending ratification by World Athletics