Fourth-placed 100m finisher Marie-Josee Ta Lou of the Ivory Coast went through from the same heat, while defending champion Jackson was in cruise control winning her heat in 22.50.
It's my first time on the track and I managed to get out strong and come through," Thomas said.
"I think I can run my world lead time again when I need to but I don't think that will be enough to win gold.
I think all the girls in the final will be under 21.60, so it's going to be fast.
The track is really fast, it really is.
Persons:
Sha'carri Richardson, Cote, Cote D'Ivoire's Marie, Josee, Lou, Sarah Meyssonnier, Sha'Carri Richardson, Jamaica's Shericka Jackson, Richardson, Allyson Felix, Jackson, Gabby Thomas, Thomas, Briton Dina Asher, Smith, Asher, I've, Shelly, Ann Fraser, Pryce, Krystsina Tsimanouskaya, Mitch Phillips, Pritha Sarkar
Organizations:
Athletics Centre, Cote D'Ivoire's, Rights, U.S, Tokyo, Thomson
Locations:
Budapest, Hungary, U.S, Ivory, Belarus