The 33-year-old Gatlin shaved of 0.12 seconds from his previous personal best mark beating his training partner Isiah Young, who finished in second in 19.93 seconds and Wallace Spearmon, who crossed the line third in 20.10. Watch video here>>
"I wanted to come out and make a statement, and that's what I did," said Gatlin.
Gatlin's 19.57 seconds in 200m is also history's 5th fastest time.
At Beijing world championships Gatlin will compete in both 100m and 200m events where he plans to challenge world's fastest man Usain Bolt. Last time these to sprinters met was back in 2013 at Moscow world championships where Bolt dominated 100m and 200m and helped Jamaica to win 4x100m gold.
There was also magnificent performance set in the women's 200m final. Jenna Prandini took the win in a new personal bat time of 22.20 seconds.
Jenn Suhr set a new world leading mark in the women's pole vault by clearing 4.82m for the win.
Alysia Montano took the win in the women's 800m less than a year after pregnancy. Montano crossed the line in 1:59.15 ahead of world championships bronze medalist Brenda Martinez 1:59.71 and Ajee Wilson 2:00.05 who ran the last 250m with one shoe.
Men's 800m final was won by Nick Symmonds who posted season's best time of 1:44.53. Erik Sowinski took second 1:44.84, while Casimir Loxsom was third in 1:45.35.
Jenny Simpson held of Shannon Rowbury for for the win in the women's 1500m final. The former world champion Simpson crossed the line in 4:14.86 while Rowbury posted 4:14.99 with Kerri Gallagher in third 4:15.81.
World champion David Oliver beat the field in the 110m hurdles posting his season's best mark of 11.04 seconds. Ronnie Ash was second in 13.13 ahead of word record holder Aries Merritt, who was third 13.19.