Kastor 9th, Rupp 4th At World Championships

The American record-holder says it was her farewell to high-level marathons.

Deena Kastor has shown she still has some racing left in her tank.

She proved as much on Saturday, taking ninth place in the marathon at the 2013 IAAF World Championships in Moscow amid hot and humid conditions that forced a third of the field of runners to drop out. The American record-holder in the marathon and half marathon, Kastor, who turned 40 in February, crossed the line in 2:36:12 to secure her first top-10 finish at the world championships since she finished sixth in the 10,000-meter run in 2007. It was her first marathon at the world championships.

Kastor has shown good form throughout 2013, having finished third in the U.S. cross country championships in February, third in the Los Angeles Marathon  (2:32:39) in March and 34th in the world cross country championships in Poland just a week later.

Kastor said the world championships marathon would be the last high-level marathon of her career. The 2004 Olympic bronze medalist said she gave it her all in her quest to finish among the top five, but the heat and humidity were just too much.

“It was a torture,” the always-gracious Kastor said after the race. “It was a hard race out there. I felt like I was trying to get those negative thoughts out, so it was a lot of mental work out there.”

Kenya’s Edna Kiplagat, the defending world champion who has trained part-time in Boulder, Colo., won the race in a come-from-behind fashion. At the 10K mark, Kiplagat was in 15th place, 29 seconds behind the leaders. She chased down Italy’s Valeria Straneo, the early leader in the race, in the final kilometers and won the race in 2:25:44 to becoming the first woman ever to successfully defend a world marathon title. Straneo was second in 2:25:58, while Japan’s Kayoko Fukushi was third in 2:27:45.

“My body was tired from the start,” Kiplagat admitted.  “When we started the race it did not react immediately, so I had to start running slowly. It was hard for me.”

Americans Dot McMahan (18th, 2:39:52) and Jeantte Faber (23rd, 2:44:03) also ran well. In all 46 women finished, but 23 more dropped out.

In other races, American Galen Rupp placed fourth in the 10,000-meter run. The 2012 Olympic silver medalist finished in season-best 27:24.39, but he was three seconds off the pace of training partner Mo Farah of the UK (27:21.71) down the homestretch. Ethiopia’s Ibrahim Jeilan (27:22:23) and Kenya’s Paul Tanui (27:22.61) were second and third, respectively. Fellow Americans Dathan Ritzenhein (10th, 27:37.90) and Chris Derrick (18th, 28:04.54) also ran season-best times.

For complete results, go to the IAAF World Championships site.

David Monti of Race Results Weekly contributed to this article.