White, 17, of Acworth, Ga., had four consecutive birdies to close out the front nine and eagled the 606-yard, par-5 14th hole. He finished with one eagle, five birdies and two bogeys at the 6,894-yard Boone Valley Golf Club.
'It's my last year to play and it's my only year to play in it,' said White, who failed to qualify for the event during his first two attempts before this year. 'You have all the best players in the country and, for me, you've got one shot at it. You take it for what it is and you just do your best.'
The Junior Championship is considered the premier amateur event for players under 18. Past winners include Tiger Woods, David Duval and Johnny Miller. This year's field has 156 participants from 38 states and seven countries.
Mu Hu, 17, of Orlando, Fla., Cameron Peck, 15, of Olympia, Wash., and Seung Yul Noh, 16, of Korea, were tied for second at 69.
Hu and his parents moved to Florida six years ago to pursue his golfing interest. He first tried to qualify for the championship as an 11-year-old and finished one stroke shy. He said he was in the hunt to earn a birth every year before finally winning a qualifier for this week's tournament.
Another 18-hole round will be played Tuesday before the players with the top 64 scores advance to the first round of match play on Wednesday. Players tied with the 64th best score following Tuesday's round will compete in a playoff to determine who will advance.
The second and third rounds of match play are scheduled for Thursday, followed by the quarterfinals and semifinals on Friday. A 36-hole match play championship round is set for Saturday.