Bolt lost his 100 title to young understudy Yohan Blake last weekend after being disqualified for a false start in the final and was in no mood to give up the gold in his favourite event.
Bolt powered home ahead of American Walter Dix (19.70) while Frenchman Christophe Lemaitre (19.80) took the bronze.
The Jamaica's time was the fourth fastest ever run. Only Bolt (with 19.19 and 19.30) and US legend Michael Johnson (19.32) have run faster.
The world record holder burst from the blocks and ate up the ground on Dix on his outside in a matter of strides.
Moving up through the gears around the bend, Bolt emerged at the top of the home straight with the race in the bag but pushed himself hard to the line to make sure there would be no more mistakes.
The 25-year-old double Olympic champion has not been at his peak this season, struggling to regain top form following a back injury that ended his 2010 season prematurely.
However, the great showman was at his imperious best on the penultimate day of competition and could still leave South Korea with two gold medals with the 4x100 relay to come on Sunday.
Only Bolt himself (with times of 19.19 and 19.30) and US legend Michael Johnson (19.32) have run quicker over 200m in history.
Bolt said “I am very happy and proud to have won here today. After the false start on Sunday, I was extremely disappointed not to have given myself the chance to defend my 100m title.
"The 200m represented a great opportunity for me to put it behind me and move on, and I’ve been determined to do so all week. The crowd was wonderful here tonight and I really enjoyed the moment.”
Dix, who also won silver in the 100 metres after taking bronzes over the 100 and 200 at the 2008 Beijing Olympics, told Eurosport he was happy with the race but still had some things he could work on.
"In Beijing I got two bronzes, I have now got two silvers, next year gold," he said in a reference to the London Olympics.