Desiree Linden, who made history in the Boston Marathon on Monday, was so unsure of her pace nearly halfway through, she cost herself crucial seconds by waiting for a friend.

Linden, the first American woman to win the Boston Marathon since 1985, spent the first hour of the race alongside fellow American and 2017 New York City Marathon winner Shalane Flanagan, even slowing down over an hour in while Flanagan used the bathroom. The two lost about 10-15 seconds on the leaders before reentering the fray.

Linden was tabbed as an early favorite to break the drought for American women, but told Flanagan she was considering dropping out of the race at the time. First, she would do her part to help push Flanagan through the finish line and give her a chance to finish first. Linden, who was the runner-up at the 2011 Boston Marathon with a personal-best time of 2 hours, 22 minutes and 38 seconds, said she felt like she was struggling to keep up with the leaders.

“Honestly, at mile two, three, four, I didn’t feel like I was even gonna make it to the finish line,” Linden told NBC Sports after the race. “I told [Flanagan] during the race, ‘If there’s anything I can do to help you out, let me know, because I might just drop out.’ When you work together, you never know what’s going to happen. Helping her helped me, and I kinda got my legs back from there.”

The bathroom break — and self-doubt — proved inconsequential in the waning miles, as Linden pulled away to win by more than four minutes over the second-place finisher, with a time of 2 hours, 39 minutes and 54 seconds in the freezing rain and vicious wind.

Flanagan, who surprised many when she captured New York City in November, finished in seventh place, nearly 20 minutes slower than her New York-winning time.

Linden, 34, and Flanagan, 36, were two of seven American women to finish in the top 10.