She only hopes that it's good enough, fast enough to put her on the Olympic medal stand.
The 23-year-old Bethel High and
McCorory ran her way into the final with a 50.19-second performance, just four-hundredths of a second behind reigning world champion Amantle Montsho of Botswana, in the second of three semifinals races Saturday before 80,000 revved-up fans at Olympic Stadium.
"The final is going to be really tough, and it's important to have some gas left in the tank for it," said McCorory, whose personal best is 50.06 seconds.
She qualified without running an all-out race. Third-place Libania Grenot of Italy, once the champion of Cuba, ran a not-close 51.18 in McCorory's semifinal.
McCorory, who will be one of three Americans in Sunday's 400 final, had the sixth fastest time in the semifinals.
The third of Saturday’s three semis had the fastest times, with the top three under 50 seconds: Antonina Krivoshapka of
AmericanSanyaRichards-Ross, the 2009 world champion and 2008 Olympic bronze medalist in the 400, took the first heat in 50.07 seconds, outrunning 2008 Olympic champion Christine Ohuruogu of Great Britain (50.22).
"I didn't think I had that much cushion coming home," she said.
Trotter's outlook on the final was simple. "It will be a big bang race."
McCorory qualified for the semfinals by winning her preliminary heat Friday. She won in 50.78 seconds, the third-fastest time of the seven heats.
The women's 400 has been in the Olympics since the 1964 Games in Tokyo, but just one American has won it over the past 12 games: Valerie Brisco-Hooks won in 48.83 seconds in Los Angeles in 1984.
Krivoshapka is likely to be the Sunday favorite, but downplayed the role Saturday.
"All the girls are equally amazing," said the 25-year-old from Volgograd.
49.81 Antonia Krivoshaka,
49.87 DeeDee Trotter, United States
49.91 Novleme Williams-Mills,
50.07Sanya Richards-Ross, United States
50.15 Amantle Montsho, Namibia
50.19 Francena McCorory, United States
50.22 Christine Ohurogu, Great Britain
50.98 Rosemarie Whyte, Jamaica
Marlena Wesh, who graduated from Landstown High School and runs for Clemson, finished last in the third heat and didn't qualify for the final. She is Haiti.