OLYMPIA FIELDS, Ill. — Libby’s Ryggs Johnston stayed late at the driving range after his first round, hoping for a “better ball-striking day” Tuesday at the U.S. Amateur Championship.

His work paid off as the15-year-old rebounded from a 78 (+8) Monday to play the first 16 holes of his second round at two-over-par before play was suspended due to darkness.

Johnston played the South Course Tuesday after tackling the longer North Course in day one. He carded eight pars on the front nine in day two, bogeying only the fourth hole.

Despite a six-stroke improvement from his first round, Johnston believes he could have gone lower.

“I played a lot better today but I just didn’t make putts,” Johnston said. “If I could have made some putts it would have been an even better day.”

Following today’s conclusion of the second round the top 64 golfers will advance to the match play portion of the event. Johnston will resume play this morning on the 17th tee at 10-over-par. The projected cut line is at +3.

Johnston is one of the youngest golfers competing at Olympia Fields Country Club and relished the opportunity to compete against the best amateurs in the world.

“(This week) has been amazing,” Johnston said. “Just to make it here is a big accomplishment. It’s a great experience.”

Australian Brad Coletta was leading at 7-under when play was suspended Tuesday night. David Oraee was in second, one shot back. More than 50 golfers in the field of 312 will complete their second round today.