Nick Warren swept his group.

The 16-year-old Central Bucks East student went 3-0 in head-to-head matchups during the national finals group stage of NBC's "American Ninja Warrior" Season 18, finishing first in his group and advancing to the next round of the competition. The episode aired Aug. 10.

"This definitely exceeded my expectations, to not just get to the finals, but to win my first three races and then get first out of my group," Warren said in an Aug. 24 New Hope News article. "It still feels surreal."

Warren, who lives in Doylestown and attends CB East, had to race three competitors one-on-one on the same course with no time to prepare for the obstacles between rounds. All three obstacles were new to him.

More than 100 people gathered at P.J. Whelihan's in Doylestown to watch Warren's first episode air. The crowd included former teachers, classmates, football and rugby teammates, coaches and members of the local ninja community.

Warren reached the national finals after sailing through the central regional finals, which aired Aug. 3. In that episode, he completed a six-obstacle course and defeated two veteran ninjas in the Tripleheader, a new three-lane race format.

He has trained in ninja competitions since age 6, when he attended a friend's birthday party at Gravity Forge Ninja Training Center in Hatboro and got hooked. He now trains daily at Nex Level in New Jersey under coach Greg Smith, who is head of the World Ninja League and built a ninja rig in the Warren family's backyard years ago.

The path to the national finals wasn't guaranteed. Warren was diagnosed with scoliosis at about age 8, and his first doctor warned he might not be able to continue sports. A spinal specialist at Children's Hospital of Philadelphia determined ninja training could continue and might strengthen his core. The scoliosis eventually stopped progressing.

Warren also plays linebacker for CB East football and rugby for the Doylestown Dragons U16 team. He began playing football in seventh grade and said the explosiveness from tackling and changing direction has helped him on the ninja course.

His mother, Stacy Warren, a national rugby coach who has led the Doylestown Rugby Academy for 24 years and teaches special education at Council Rock High School North, said the sport has taught her son how to handle failure.

"Ninja is a very unforgiving sport," Stacy Warren said in the same New Hope News article. "You fall and you're out."

Warren credited his younger sister Alex, who has a sensory processing disorder and dyspraxia, as a major source of motivation. He also founded "Ninja for a Cause" about eight years ago, a fundraising effort supporting autism awareness and other causes including the AJ Foundation.

Season 18 introduced a new all-racing national finals format with a $250,000 grand prize. Warren was 15 when the season was taped in Las Vegas last September. NBC has not announced when Warren's next round will air.