Sen (71) among leaders at World Junior Challenge

Carl Yuan, 15, on the first tee during the U.S. Open local qualifier on Thursday at Timacuan Country Club.

Carl Yuan, 15, on the first tee during the U.S. Open local qualifier on Thursday at Timacuan Country Club.

Girls Rankings »

#NameYearStateRating
1Alison Lee2013CA68.26
2Esther Lee2013CA69.61
3Casey Danielson2013WI69.64
4Casie Cathrea2013CA70.09
5Ashlan Ramsey2013GA70.33

Boys Rankings »

#NameYearStateRating
1Robby Shelton2013AL67.85
2Jim Liu2013NY68.49
3Scott Scheffler2014TX68.71
4Andy Shim2013GA68.78
5Rico Hoey2014CA69.31

Cao Sen may not be the oldest and most experienced player in the World Junior Challenge field, but on Friday, he shot the lowest score.

Sen, a Lake Mary, Fla., native, shot 1-under 71 on the Island Course at Innisbrook Resort and Golf Club to take the first-round lead in the boys 14-and-under division. Sen, who made a tournament-high five birdies in the opening round, leads Sachin Kumar of Trinidad and Tobago by a shot.

Selena Costabile of Thornhill, Ontario, leads the girls division after carding a 3-over 75 on the Island Course. She holds a one-stroke advantage over Maria Alejandra Villalobos of Gainesville, Fla., and Hana Furuichi of Orlando, Fla.

“It was cold this morning and a little hard to get going,” Costabile said. “I tried not to worry about my bogeys. I knew there were birdie holes coming up and that allowed me to stay confident.”

There is a three-way tie for first place in the boys 15-19 division as Italy's Renato Paratore, and Lake Mary's Robin Wang and Jerry Zhu all find themselves at 1 over after opening-round 72s on the Copperhead Course.

There are 11 players within two shots of the lead, including notables Eric Macrow of Kingston, Ontario, and China's Carl Yuan, who are both T-6 after shooting 3-over 74.