Gold that glitters
Drawn in lane six, he tracked the USA's Kenny Bednarek through the first 100M before taking a narrow lead that he held down the straight to claim victory in 19.62, a personal best time that lifted him to eighth on the all-time list.
"I went back after the 100M and I was a little bit disappointed in myself, that I could've done better," De Grasse told World Athletics.
"I said: 'I gotta go and get this 200, I gotta go and get it'. I knew the Americans were going to push me, and they were going to take me to a personal best. It's been five years since I had a personal best, so it was just good to get that finally out the way."
Korir leads Kenyan 1-2
Meanwhile, East Africa, the world's foremost cradle for distance runners, finally asserted itself at Tokyo 2020, as both Kenya and Uganda won their first gold medals in the stadium.
It has been a slow start for distance powerhouse Kenya, but they finally broke through in style, claiming both the gold and silver medals in the men's 800M -- as Emmanuel Korir crossed the finish line in 1:45.06, just ahead of Ferguson Rotich (1:45.23).
Chemutai does Uganda proud
History was made in the women's 3,000M steeplechase final as Peruth Chemutai sprang an upset to become the first Ugandan woman to win an Olympic medal.
With 600M to go, front-running Courtney Frerichs of the USA had a handy lead, but Chemutai patiently reeled her in and took the lead with 300M to go, surging away to win in a personal best time of 9:01.45.
Fine night
In the heptathlon, Dutchwoman Anouk Vetter leads with 3968 points from Belgians Noor Vidts (3941) and Rio Olympic champion Nafi Thiam (3921).
It was a fine night for Polish athletics as the central Europeans claimed three medals across two events.