The Kiwi won the event with a throw of 20.95 metres, 25 centimetres further than her gold medal throw at the London Olympics.
It was the New Zealander's second Diamond League victory in two weeks, and third of the season, after winning in Stockholm last weekend.
Her best effort was more 1.35m further than second placed Michelle Carter of the USA.
Olympics silver medalist Yevgeniya Kolodko finished in third, more than two metres behind Adams.
Adams passed 20 metres on all three of her recorded throws.
Results:
Valerie Adams (NZL) 20.95, 1; Michelle Carter (USA) 19.60, 2; Yevgeniya Kolodko (RUS) 18.64, 3; Cleopatra Borel-Brown (TRI) 18.50, 4; Natallia Mikhnevich (BLR) 18.48, 5; Irina Tarasova (RUS) 18.22, 6; Josephine Terlecki (GER) 17.47, 7; Chiara Rosa (ITA) 16.98, 8
