"That's insane," Johnson said of her 100 time. She never had broken 12 seconds before running 11.99 in her qualifying heat.
In other highlights of the meet that brought together the state's top track and field athletes, Oakcrest senior Fabian Santiago became just the second boy to win three events at the Meet of Champions with victories in the 100 (10.59) and 200 (21.52) as well as an anchor leg on the Falcons' victorious 4x100 relay.
"It all goes back to the training we do," Santiago said.
The only other boy to win three events was Winslow Township's Reuben McCoy, who won the 200, 400 and intermediate hurdles in 2004.
Johnson played eight games for her ASA team, the New Jersey Gators, in a tournament in Shamong in Burlington County over the weekend. She said she needed an ice-bath to soothe her legs on Sunday night.
"I was really nervous about this because my legs were so sore," Johnson said.
Johnson said she got off to a "great start" in the 100 finals and never hesitated in pulling away from the field. North Brunswick senior Kaitlyn Davis, who has tied Johnson in the Group 4 state final on June 2, was second in 11.96.
"It was the last 100 of my life," Johnson said.
Shawnee coach Beth Ritter called Johnson's victories "surreal" given her circumstances.
Johnson played softball as a freshman and sophomore at Shawnee but decided to run track as a junior to see how her speed would translate to another sport.
Fifteen months later, she was the fastest girl in the state.
"She's the fastest girl to ever walk the halls of Shawnee High School," Ritter said. "It's just unbelievable."
Santiago won the 100 comfortably, as Ocean Township's Mike Andre was second in 10.74 and Cherry Hill East senior Brian Regan was third in a personal-best time of 10.76.
Santiago was challenged in the 200 but held on the victory.
"No way they were catching me," Santiago said.
Cherry Hill East senior Alex Reber took third in the 400 in a time of 48.26, and Eastern senior Tom Carr was third in the javelin with a 187-11 effort.
Vineland senior Maria Jimmenez took second (143-09), and Haddonfield senior Katie Johnston took third (138-02) in the javelin, while Haddonfield junior Emily Carson (18-6 1/4) took third in the long jump.
Cherokee senior Megan Lacy took third in the 3,200 meters.
Oakcrest junior Daniel Jefferson won the high jump with a personal-best leap of 6 feet, 6 inches. The top six finishers in the event all jumped 6-6, but Jefferson took first on fewest misses.
"I'm shocked," Jefferson said. "I came here just hoping to get a medal. I never thought I would win."
Willingboro senior Isaac Williams was second in the high hurdles in 13.92. Trenton senior Jermaine Collier won the race in 13.67.
"Second is good, but I wanted to get first," said Williams, who has signed with the University of Houston.
Haddon Heights junior Dominique Irons took second in the triple jump in 47-11. Sayreville senior Emeka Eze won the event in 48-2.
Kingsway senior Tom Cooke took fifth in the 1,600 in 4:11.84 in a race won by Toms River South junior Chris Marco in a meet-record time of 4:07.31.
Delsea junior Josh Awotunde finished fourth in the discus at 169-5, while Pleasantville junior Isaac Clark took fifth in the 800 in 1:53.58.
Oakcrest literally got off to a fast start as the Falcons won the 4x100 relay early in the meet. The team of Stephen Adkission, Reggie Morton, Darnell Charles and Santiago won the race in a time of 42.09.
Contact Phil Anastasia at 856-779-3223, firstname.lastname@example.org, or @PhilAnastasia on Twitter.