With back-to-back first-place finishes already in the bag, Greg Poffenroth may have been in search of a little extra motivation at the start of his third consecutive appearance in the San Juan Island Half-Marathon.

If so, he got it, and then some.

With just over a mile to go to the finish line, the 29-year-old Bothell man felt his strength begin to sag and Robert McWilliam was still there nipping at his heels.

“It felt like he was a lot closer than I wanted him to be,” said Poffenroth, who managed to outpace McWilliams down the home stretch and up the final hill of the 13.1-mile course, besting the 44-year-old Englishman by 33 seconds to claim a third-straight half-marathon title.

Seattle’s Robert Nelson finished first among 47 runners that tested their mettle over the 26.2-mile course of the full marathon. At a pace of six minutes, 54 second per mile, Nelson, 33, crossed the finish line in 3:00:55, eight minutes ahead of runner-up and fellow Seattleite Matthew Burkhardt, and 25 minutes ahead of the mark set by 2012 winner Tim O’Brien, of Maple Valley. Celina Santi, 29, also of Seattle, was first among the women’s field of full-marathoners, at 3:27:05.

Not only did Poffenroth claim a third consecutive first-place title, finishing in 1:25:31, the first-time father of a 10-month-old son did so on Father’s Day.

The father of three, McWilliam, runner-up in the Half, took a break from business meetings in Seattle to run a half-marathon in nearby Burlingtn on Saturday, where his finish time ballooned beyond normal after taking a wrong turn on the course, and then to tackle the San Juan Island course and its hills for the first time the following day.

“It’s an absolutely fabulous course,” he said. “The scenery is breathtaking but still so varied. The hills are really challenging, or really exhilarating depending on whether you’re going up or down.”

Poffenroth was one of many fathers pounding the pavement in the 11th annual San Juan Island Marathon, Half Marathon, 10K run, Sunday, June 16, sponsored by Kings Market. With a total 229 people registered for all three events combined, participation in the 2013 marathon was up 20 percent over the previous year’s total, according to Paul Hopkins of San Juan Island Fitness, marathon co-coordinator.

Hopkins said that the collapse of the I-5 bridge over the Skagit River on the eve of the Memorial Day weekend and the ensuing detour routes apparently did not dissuade many from taking part in the run.

“We’re not sure if it’s because of a better economy or the later start date,” Hopkins said, “or the challenge of getting here with a downed bridge.”

Those infamous hills may be a thing of the past, as the marathon, and companion events, will switch to a new format and new location beginning next year. After 11 years as a road run, the island’s premier long-distance running event will transform into a twin triathlon featuring two distances, Olympic and Sprint, a Friday night kids triathlon and will be hosted by Lakedale Resort.

Local runners finishing at the front of their respective events include San Juan Island’s Ross Lockwood, fourth place in the half with a time of 1:39:59, Brendan Cowan, finishing eighth in the half, 1:43:04, and Kirby Anderson, at 1:44:44, 13th among 113 half-marathoners. At 3:19:25, Friday Harbor’s Elliot Thomsen finished fifth in the marathon, Irinia Bell finished 14th, 3:57:35, at 24-year-old Talia Loucks finished her first-ever marathon in 4:33:34, 26th overall.

For a complete list of runners and finishing times, click here.