Perri Shakes-Drayton ran another sub-54 seconds to finish second behind Zuzana Hejnova in the 400m hurdles at Saturday's Diamond League meeting in Paris.
Britain's indoor 400m champion clocked an impressive 53.96 seconds as she continues her preparations for the upcoming World Championships in Moscow.
The 24-year-old tweeted after the event: "Another sub 54 in the bag. Good going. Roll on world champ trials next week at Birmingham next weekend. #ParisDL"
Hejnova remains undefeated in all four 400m hurdle events she has entered this year. The Olympic bronze medalist ran 53.23 seconds to claim victory in France this weekend.
By comparison with the Czech, Shakes-Drayton ran a quicker 53.82 seconds to seal a victory of her own in Birmingham last week, and will be hoping to better that time when she returns to action next week.
"I have two more races to go," she explained in an interview with the BBC. "I am going to the trials next weekend, I have not made the team yet so that will be important.
"Then I have the Anniversary Games in London."
Paris Diamond League: 400m hurdles
1. Zuzana Hejnova 53.23 - 2. Perri Shakes-Drayton 53.96 - 3. Georganne Moline 54.19 - 4. Denisa Rosolova 54.38 - 5. Kaliese Spencer 55.22 - 6. Ristananna Tracey 55.33.