No Sibling Rivalry for Danielson Siblings August 14, 2013 | Brookline, Mass. By David Shefter, USGA

Charlie Danielson, of Osceola, Wis., posted a 3-and-1 victory over Chase Koepka to reach the Round of 16. (USGA/John Mummert)

Contrary to popular belief, Charlie Danielson has not spent a lot of time competing against his two decorated sisters: Lindsay and Casey.

Older sister Lindsay, a four-time Wisconsin high school champion, recently completed her college career at the University of Wisconsin and has decided to retire from competitive golf.

Younger sister Casey, an American Junior Golf Association All-American and 2011 U.S. Women’s Amateur quarterfinalist, also won four Wisconsin high school titles and will be a freshman at Stanford University this fall. On Wednesday, she helped the USA win the Junior Solheim Cup at Inverness Golf Club in suburban Denver, a week after suffering a tough first-round loss at the Women’s Amateur to Kendall Prince.

Charlie is carving his own golf legacy. A two-time state high school champion, the 19-year-old from Osceola helped the University of Illinois stun top-ranked California-Berkeley in the semifinals of the NCAA Championship in June before the Fighting Illini came up short in the final against Alabama.

On Thursday morning at The Country Club, Danielson produced a 3-and-1 victory over Chase Koepka to reach the Round of 16 in just his second U.S. Amateur appearance. In a battle of giants, the 6-foot-5 Danielson faced 6-foot-4 Brandon Matthews later Thursday for a spot in the quarterfinals.

Just keeping up with the golfing trio is a challenge for parents Craig and Liz Danielson. Both were in Charleston, S.C., last week for the Women’s Amateur and they made the trek to Boston this week to watch Charlie.

"They’re big fans of each other," said Craig. "But Lindsay can’t watch Charlie play. It’s just too nerve-racking. It’s a totally different game. Usually the girls are straight down the middle and the guys are letting it fly."

Charlie received a congratulatory text from Casey on Wednesday night after his first-round victory over 2013 Canadian Amateur champion Eli Cole, of Beverly Hills, Calif. Charlie congratulated Casey on her halved match against reigning British Ladies Open Amateur champion Georgia Hall in the Junior Solheim Cup.

"We support each other and we’re happy for each other," said Charlie. "A lot of people think [we play a lot together]. But we don’t play much together. We practice every now and then, but we’re always traveling different places."

Golf wasn’t even Charlie’s first love. Always tall for his age, Danielson was a standout basketball player in junior high, only to have knee issues halt any hopes of playing in college. He has had multiple knee operations, including micro-fracture surgery 3½ years ago.

"Up until the last two years, he couldn’t get behind the ball and read greens," said Craig Danielson. "His knees made him have to forget about basketball and allowed him to concentrate on golf."

Danielson was recruited by virtually all the schools in the Big Ten, but settled on Illinois because of Coach Mike Small, a former PGA Tour player who has played in multiple PGA Championships and U.S. Opens.

Under Small’s tutelage, Danielson grew as a player in his freshman season. When he qualified for last year’s U.S. Amateur at Cherry Hills Country Club, Danielson went in with a just-happy-to-be-there attitude. With a year of college under his belt, Danielson had a much different mindset coming into this week.

"I was still a young kid last year at the U.S. Am," said Charlie. "I hadn’t had the big experiences in big tournaments. This year I came to compete."

Illinois made quite a run at the NCAAs, earning a spot in the eight-team match-play draw, then defeating defending champion Texas. Danielson defeated Toni Hakula, who would be the runner-up at the British Amateur later that month, 1 up.

In the semifinals, the Fighting Illini stunned top-ranked and No. 1-seeded Cal, with Danielson producing a clutch 3-and-2 win over Joel Stalter.

Danielson lost the next day in the championship match to Alabama’s Trey Mullinax, 1 down, but that experience was a springboard to the summer campaign.

A few weeks later, he was runner-up to Jordan Niebrugge, the 2013 U.S. Amateur Public Links champion, by one stroke at the Wisconsin Amateur. He also competed in the Western Amateur and the Sunnehanna Amateur.

Danielson made the match-play draw by shooting 143 in stroke-play qualifying at The Country Club (72) and Charles River Country Club (71), the companion course.

He had an up-and-down performance against Koepka, a 19-year-old sophomore at South Florida. Three consecutive three-putts from No. 12 prevented him from closing out the match earlier. But Danielson, who only lost one hole during that stretch, delivered when he had to, stuffing his approach on No. 15 to 3 feet for a winning birdie and a 3-up lead. Koepka rolled in a 7-footer for birdie on 16 to extend the match, but Danielson birdied the 17th hole from 8 feet to close him out.

Late Wednesday in Denver, Casey got the opportunity to hoist the Junior Solheim Cup trophy.

If Charlie can produce four more victories this week, he will be holding the Havemeyer Trophy in his hands.

David Shefter is a senior staff writer with the USGA. Email him at dshefter@usga.org.