Lendl finished at four-under-par 209 for her first American Junior Golf Association (AJGA) Invitational title. In three rounds, she totaled 11 birdies, seven bogeys and 36 pars at White Manor Country Club.
'This is the biggest win I have ever had and to have Betsy Rawls' name on it is such an honor,' said Lendl.
Kristina Wong, Lisa McCloskey and Vicky Hurst tied for second place at one- over-par 214. Each shot rounds over par on Thursday.
Joanne Lee shot a three-under 68 to move into fifth place at four-over-par 217.
Lendl, a 2005 honorable mention Junior All-American, opened her round with a bogey at the first -- but it would be her only dropped shot of the day. She rebounded with consecutive birdies at the third and fourth holes to get under par on the front nine.
After parring five straight holes to begin the back nine, Lendl collected birdies at 15 and 17 to move to four-under for the tournament.
After that, victory was all but assured.
'I played really well the whole day today,' Lendl said. 'After the birdie on No. 15, I really felt like I was in control.'
Lendl's younger sister, Isabelle, a second-team All-American, finished in a tie for 11th place at eight-over-par 221. Isabelle Lendl shot a three-over 74 in her final round.
More than 160 former AJGA players are currently competing on the PGA and LGPA Tours, including last year's Betsy Rawls winner, Morgan Pressel.