Britain's Marilyn Okoro clinched a thrilling 800m victory at the Thales FBK-Games in Hengelo, Holland.
Okoro faces stiff competition for a World Championships place
Okoro remained calm down the final straight to snatch victory from Lucia Klocova and British team-mate Jenny Meadows in two minutes 0.7 seconds.
Marlon Devonish clinched third place in his opening 100m race of the season.
European bronze medallist Andy Turner finished third in the 110m hurdles in a season's best of 13.47s, despite hitting several barriers.
He remained in contention until the closing stages but finished behind America's Ryan Wilson (13.33) and Holland's Greg Sedoc (13.37).
Okoro said she could run faster, but admitted competition for places at the World Championships in August would be fierce.
She said: "We've got some of the best 800m girls in the world and it is going to be hard to be picked.
"There's a long way to go and I'm sure my times will get faster."
Olympic 4x100m relay gold medallist Devonish finishing behind Churandy Martina and Shawn Crawford.
Martina clocked 10.14s to hold off the challenge of the USA's Olympic 200m champion by 0.08s.
Devonish clocked 10.25s then said: "I'll take that. It was a loaded race and I came through strongly at the end despite being in lane nine."
Joice Maduaka showed good early-season 100m form when taking fourth place just ahead of team-mate Jeanette Kwakye.
Maduaka posted 11.44s with Kwakye running 11.49s, but they were no match for world indoor 60m champion Me'Lisa Barber.
The American defeated last summer's European gold medallist Kim Gevaert of Belgium by one hundredth of a second in 11.35s, with Mikele Barber, also of the USA, third in 11.41.