Tracey booked her place in the final with 54.80. She led into the straight, but Zuzana Hejnova of Czech Republic finished very strong to take the top spot in a season best, 54.55.
In semi-final 2, Russell, who led coming off the curve, but dropped back slightly, again took the lead before easing down across the line in 54.92.
American Ashley Spencer, who trailed Russell for the first 300 metres before briefly taking the lead in the straight, then lost it and got it back a second time, when the Jamaican closed it down with five metres to run.
Spencer’s winning time was 54.87secs.
Nugent secured her spot as one of the fastest qualifiers with a personal best 54.98.
American Dalilah Muhammad, the favourite for the event, was very comfortable in topping the semi-final in 53.89 ahead of Sara Slott Petersen of Demark, 54.55