Alexsandr Tammert threw a world season's leading 68.48m in the men's Discus to improve his own Estonian national record on 27 March.
The throw came between rainstorms at the UT-Arlington Invitational in Arlington, Texas.
Tammert, 31, who was seventh in the World Championships in Paris, had a previous national record best of 67.75 which he set in Tartu on 23 May 2002.
Tammert was the 2001 World Student Games champion, and was fifth in the 2002 European Championships.
NB. Olympic and World champion Virgilijus Alekna of Lithuania was entered for the competition but because of the poor weather conditions did not throw.