STONEHAM, Mass. – Roos Karssemeijer planned to stay home on Saturday, Nov. 2, rather than running the 32-mile race at the Trail Animals Running Club’s annual Fells Winter Ultra.

The prior two weeks had been busy, between work and a cross-country trip to run an ultramarathon in California, so she was exhausted. Besides, the friend she’d signed up to run with had to cancel.

“I signed up with a colleague, and she couldn’t make it because she was traveling, so I was just on my own,” said Karssemeijer, 31, who lives in Boston. “Also, I did the North Face 50K (in San Francisco) two weeks ago, so I thought maybe this wasn’t the best idea because I’m not really trained for this race and my work has been very busy so I sleep very little during the week. I thought, ‘Why am I signed up for this? This is a bad idea.’”

Karssemeijer emailed Race Director Jeff LeBlanc and told him she was going to give up her spot in the field. LeBlanc pushed back and made a convincing case.

“He emailed me back and was like, ‘Well, you should just come. You have nine hours (to finish),” Karssemeijer said with a laugh. “And I thought, ‘That’s true!’ It’s a nice day and it’s not going to rain, so that’s why I decided to come out.”

It turned out she didn’t need nine hours to finish – quite a bit less, in fact. She circled the eight-mile, rocky, rooty, leaf-blanketed Skyline Trail loop four times and led from start to finish. She completed the first loop in 1:25:17; Elise Huysman was six minutes back, followed closely by Leah Lawry and Elizabeth Collins.

Runners had the option of running the course loop clockwise or counterclockwise, which made it tough for runners to know exactly what place they were in as the race unfolded. Karssemeijer didn’t mind, though. She said it created camaraderie on the course.

“I actually found that very nice because you could see people at the halfway point (of each loop) so you are able to build a connection with people,” Karssemeijer said. “I really liked that. You could kind of cheer each other on at the halfway point, so you kind of get to know people that are running in the other direction.”

Karsemeijer extended her lead to nearly 15 minutes by the time she was through two loops, and she led comfortably the rest of the way while cruising to the victory in 6:38:51.

“I had no idea (that I won),” Karsemeijer said shortly after finishing. “I had a feeling there were not that many women in front of me, but I didn’t really know. My goal was just to finish.”

The closest battle was for the final spots on the podium between Huysman, Lawry, Collins, Nicole Ponte and Tammy Volock. Lawry – who won the 32-miler in 2014 and 2016 and finished third in 2015 – held her ground in the top three throughout the day. The 34-year-old from Charlestown, N.H., traded positions multiple times with Huysman, a 19-year-old from Pawtucket, Conn., who was making her Fells debut. Lawry and Huysman ran the first two loops within seconds of each other before Lawry built a nearly 10-minute lead during the third loop. Meanwhile, Ponte and Volock closed in on Collins, and then Ponte – who had climbed to fourth – closed in on the top three. She was just seconds back of Huysman after 24 miles, and the race was on.

Huysman and Ponte began their final loop just seconds apart and took off in pursuit of Lawry. Both narrowed the gap as Lawry’s pace slowed. Huysman ran the fastest final loop split of any of the women, and the result was a dramatic neck-and-neck dash to the finish line where Huysman and Lawry crossed side by side. They tied for second place in 6:57:50. Moments later, Ponte dashed across the finish line. The 19-year-old from Dartmouth, Mass., finished in 7:00:23, good for fourth place.

Volock, who began the day in eighth place, caught Collins during the final loop and the 44-year-old from Portland, Maine, finished fifth in 7:07:39. Collins, 33, of Dover, N.H., finished a few minutes later in sixth place in 7:15:52. More than 30 minutes separated the first six from the rest of the field.

Twenty-two women finished the 32-mile race, the most in the seven years that records are available for the event. Karssemeijer ran the fourth-fastest time during that span, trailing only Hanna Lippe’s 6:22:29 and Kristen Peterson’s 6:32:46 from 2015 and Lawry’s 6:27:23 from 2016. Huysman and Lawry’s second-place tie landed them the ninth- and 10^th-best times on the course.

For a recap of the men’s Fells Winter Ultra 32-mile race, click here.