The Swede fell back in the lead and crossed the finish line as seventh with a time of 1.44,02, less than a second behind his Swedish record of 1.43,13.
The winner was the Spaniard Mohamed Attaoui, who described the race as "brutal".
I felt very strong in the first lap, and those who went out too offensively had to pay in the end. I utilized the opening on the inside, he says according to the Diamond League's website.
The discus thrower Vanessa Kamga was the second Swedish participant on Midsummer Eve. She came eighth after having thrown 60,69, four meters from her season's best.
