Great Britain's Greg Rutherford suffered an ankle injury at a meeting in Italy despite claiming victory in the long jump.
The London 2012 gold medallist, 30, jumped 7.95m in the third round in Gavardo - a meeting record - to beat Italy's Camillo Kabore (7.45m).
But Rutherford later tweeted: "Sadly not to be today. The ankle injury I've been dealing with hasn't held up.
"I think a hospital trip is in order for scans and treatment."
Rutherford won the Great City Games last weekend in Manchester as he recorded 8.18m with his final jump.
He is targeting a successful defence of his title at the World Athletics Championships in London in August, before defending his Commonwealth and European crowns in 2018.
Other Britons in action in Gavardo:
Danny Talbot recorded a meeting record as he won the 200m in 20.31 seconds.
Reece Prescod won the men's 100m with a time of 10.11 and Daryll Neita took victory in the women's in 11.39.
Richard Kilty - third, men's 100m (10.18) and men's 200m (20.51)
Ojie Edoburun - fourth, men's 100m (10.20)
Thomas Somers - fourth, men's 200m (21.04)
Imani-Lara Lansiquot - third, women's 100m (11.48)
Serita Solomon - third, women's 100m hurdles (13.45)
Leah Barrow - fifth, women's 800m (2:07:69)