Honolulu resident Tim Marr's debut at the Ironman World Championships in Kona last weekend came with as much caution as anticipations.

No one doubted that Marr, who has dominated the local triathlon scene for the past several years, had the will and ability to perform well. Yet, for those with intimate first-hand knowledge the legendary race warned the up-and-comer to temper his expectations.

The race is unmatched in both its magnitude of importance within the triathlon world and its ability to humble the world's most accomplished endurance athletes. And, Marr's counsels emphasized, even the most promising young triathletes have been known to falter in the rarified air of the sport's most elite field.

Some 1,736 competitors finished the event, which is composed of a 2.4-mile swim, 112-mile bike and 26.2-mile run.

"This is our Super Bowl," Marr said of Kona. "That's how big it is to us. "I grew up watching it and I dreamed about one day doing it. But to actually be out there, for that to become a reality, was incredible."

Marr, 29, set a goal of placing in the top 20, knowing how ambitious the mark was given his lack of experience on the brutal course.

"Physically, I felt I could do it," he said. "I was concerned, though, if I was mentally prepared enough."

He was.

Despite struggling mightily in the second half of the 112-mile cycling leg, Marr finished in 15th place overall in a time of 8 hours, 48 minutes and 50 seconds.

"I had set a big, lofty goal for myself and people who had done the race before kept telling me, 'Don't get down in you can't do it,' " Marr said. "I knew there would be a learning curve, so I was thrilled and happy to have finished where I did."

Though Marr said he always feels confident with his swimming, the first minutes of the race were an eye opener.

"There were a hundred pros at the start, all trying to bump their way to the front," he recalled. "It was wild, really vicious. It was kind of like a huge fist fight with all of the contact that went on."

After a quick transition, Marr found himself locked in to a horde of some 40 cyclists on the loop around town.

"We had to make a series of really sharp turns and all the while everyone is trying to lose each other," he said. "It was really fun."

Marr eventually broke away and was able to overtake several strong German riders on the long, uphill approach to Hawi.

On the return leg, however, Marr began to falter as he battled high winds and rising heat.

"It was really hard to keep focused and confident," he said. "Other riders started passing me and that started to really get me down."

Beset by cramps in the first mile of the run, Marr ran into a Port-A-Potty at Mile 2 to douse himself with water, then downed Coke and Gatorade to refresh his overheating body.

By the time Marr ran into his father's arms at the finish line, he was physically and emotionally spent.

"I cried," he said. "It was very emotional for me."

The race was also a vindication of Marr's long-held assertion that triathletes didn't need to leave Hawai'i to train and perform at the highest level. Marr had spent two weeks in Kona to familiarize himself with the course. He spent the rest of his training cycle on O'ahu.

"I was a little intimidated because there are German athletes with $1 million contracts who are like superheroes in their own country," he said. "To be able to compete with them was special given how much prestige they have in the sport. I proved you can do this at this level and not have to go somewhere else."

In fact, Marr was one of several Hawai'i triathletes who translated long, grueling hours of training in the islands into strong performances on the sport's grandest stage.

Rachel Ross, 32, followed up a string of impressive local wins with a 10:06:33 finish. And while it was her slowest finish at the event, she still placed third in her age group and fourth among amateur women.

Veteran local triathlete Katherine Nichols, 42, turned in one of the grittiest performances of the day, overcoming cramps and vomiting to complete the race in 10:41:27.

The race also featured a pair of wow-inducing debuts from two of the state's most accomplished swimmers, Noa Sakamoto and John Flanagan. Sakamoto, 22, led all swimmers with a current-shredding time of 47:01; Flanagan, 33, finished a second behind.

Flanagan, who took up triathloning just 10 months ago, would finish the race in 78th place overall in 9:22:33, distinguishing himself as the second Hawai'i finisher (and first Hawai'i amateur) overall.

After swimming comfortably ahead of the rest of the pack, matching training partner Sakamoto stroke-for-stroke, Flanagan suffered a flat tire early in the bike leg, his first since his initial week of training. Still, he recovered quickly with the help of a support truck and continued on.

After surviving 35 mph crosswinds on the return leg, Flanagan ran a strong, well-strategized marathon, allowing himself brief walking breaks every four miles down the stretch.

"As much as this is a physical challenge, it's even more mental," Flanagan said. "There are lots of ups and downs throughout. You feel good for a while, then you feel completely humbled. You're going at a good pace, then it seems like you're not going anywhere. This was one of the hardest things I've ever done."