For many of the 23,197 finishers, the Marine Corps Marathon’s 40th anniversary was a reason to come out and celebrate an old friend — the race that gave them their marathoning start, the reliable fall race that everyone turns out for and, for locals, familiar training ground.

But when the pageantry and rain cleared, two newcomers took top honors. Trevor Lafontaine, 22, a recent West Point graduate and debut marathoner, ran away from the field in the last seven miles to win the men’s race in 2 hours 24 minutes 24 seconds. Twenty-one minutes later, Jenny Mendez Suanca, 35, a three-time marathon winner in her native Costa Rica, scored a victory in her first international marathon, running 2:45:55.

Their strategies played out to their respective levels of experience. Suanca, who was running only her fourth marathon, stormed to a 40-second lead over her pursuers barely three miles in, though she relinquished the lead after the race’s midway point. By the time she reached the 18-mile mark on the Mall, she was ready to take over and pulled away for a 7:34 margin over Christine Taranto, 30, a Marine who was running her fourth Marine Corps Marathon.

Suanca started running seven years ago with the support of her husband, himself a runner and a coach, and though she likes the supportive running culture she has at home, the East Coast weather agreed with her.

“It was cold at the beginning. I was struggling with it, but I got warm as the race went on,” she said through an interpreter. “It was much less humid than Costa Rica.”

Lafontaine, who had never raced beyond 10 kilometers, started conservatively, running with Daniel Schlich, a teammate on both the U.S. Army and West Point teams, until he worked his way up into a chase pack near the halfway point. He shared the lead with Oscar Mateo Santos, 32, a contractor for the Mexican military, before making his move at 19 miles. When Santos tried to follow him, he was hindered by a cramp in his quadriceps and hamstring and spent nearly two minutes trying to massage it out so he could give chase. But the gap was too much to make up, and Lafontaine cruised to a win by 1:43.

“I just didn’t know what was going to happen after 22 miles,” he said. “I was a little nervous, but every step felt all right, so I relaxed.”

Lafontaine is on a temporary assignment coaching the West Point prep school’s cross-country team, which allows him some flexibility to train while helping him appreciate his freedom after running three seasons of cross-country and track each of the previous four years. His mother is a high school cross-country coach in Connecticut.

Back in the pack, runners reported delays getting to the starting line following the introduction of several security checkpoints on race morning. That didn’t stop Al Richmond, 76, of Arlington, and Will Brown, 69, of Raleigh, N.C., from finishing their 40th consecutive Marine Corps Marathons. They are the only remaining “Groundpounders” to complete all 40 races.

The marathon will move its race expo in 2016 to the Gaylord National Resort and Convention Center in Oxon Hill following years at the D.C. Armory and this year at Walter E. Washington Convention Center. The move, billed by race organizers as an opportunity to share the race’s economic impact with Prince George’s County, has been criticized by local runners for its lack of Metro accessibility. Organizers plan to offer shuttles from the Huntington Metro station.

Out of 23,197 runners who finished the 40th Marine Corps Marathon, Trevor Lafontaine from Cornwall, N.Y. finished the 26.2-mile race in just 2 hours 24 minutes 24 seconds. (WUSA9)

sports@washpost.com