Sophie continues build-up to Euros
Wlodarczyk was beaten for the first time in almost four years, as she finished ninth in the women’s hammer competition with a best throw of 65.71m.
China’s Luo Na won with 75.02m, with Olympic bronze medallist Hitchon seventh with 68.74m.
Hitchon is building up to the European Championships in Berlin in August.
Halle was her first outing in month, having bounced back from her Commonwealth Games disappointment in April with victory in Berkeley, north California.
There she won the hammer with a throw of 73.22m, just over a fortnight after three no-throws saw the favourite for the gold medal bow out of the final on the Gold Coast.
Hitchon had eased back into action five days after the Commonwealth Games final by throwing 70.03m to win the Spring Fling Elite/Open event back in California at Salinas.
But her effort in Berkely remains her best of the season to date, topping the 71.41m in the pre-Commonwealths Stanford Invitational event warm-up event in Palo Alto, California.