She beat Sarah Lavin who clocked a personal best of 12.73s for 2nd and Pia Skrzyszowska in 12.78s in 3rd place.
Tobi finished in second position in the 100 metres hurdles event at the Lausanne Diamond League on Friday.
Puerto Rico’s Jasmine Camacho-Quinn won the race with a time of 12.40s.
Amusan clocked a time of 12.47s equaling her personal best for the season.
The third position went to Tia Jones, who ran a time of 12.51s.
It was a slight improvement from Amusan, who finished in third position behind Camacho-Quinn and Tia at the continental tour event in Ostra on Tuesday.
