Blumenherst, the Division I player of the year, advanced to Saturday's semifinals at Crooked Stick Golf Club.
'I thought I played great. I hit the ball really solid,' Blumenherst said. 'I'm playing well and have a lot of confidence in my game.
'It was a lot of fun to have a lot of Indiana family and friends. It's also a little tough on the competitor,' she said of the support from the spectators.
Blumenherst, who grew up in Fort Wayne, Ind., and lives in Scottsdale, Ariz., was cheered on by about 15 family members. She birdied two of the first three holes, increased her lead to 6-up with a 30-foot birdie putt on the 12th hole and was 5-under par when the match ended two holes later.
It was the third straight quarterfinal loss in the tournament for Lee, who was born in South Korea and lives in Henderson, Nev.
In other quarterfinals, Maria Jose Uribe of Colombia, who will be a freshman at UCLA in the fall, beat 2008 Duke recruit Mina Harigae of Monterey, Calif., 5 and 4; and 15-year-old Ha Na Jang of South Korea scored a 5 and 4 win over 12-year-old Alexis Thompson of Coral Springs, Fla., the youngest player to get this far in the 107-year history of the tournament.
'I hit some really ugly shots,' Thompson said. 'I was pretty frustrated. I just don't know what happened to me. I really don't.'
Jang, playing in the Women's Amateur for the first time, shot a 33 on the front nine to take control of the match.
'She didn't make a mistake out there,' Thompson said. 'I'm really happy how far I made it. I wish I would have won today's match, but I knew I was going to have an off-round sooner or later.'
In the last quarterfinal, South Korea's Jennifer Song played defending champion Kimberly Kim of Hilo, Hawaii, who was trying to become the tourney's first repeat winner in 11 years.