The 22-year-old American trailed Britain's Adam Gemili in the early stages but ran a good bend before storming home in the last 50 metres to take victory in Doha in 19.83s.
"This is my first one and I don't know a lot of people who can say they came into their first World Championships and grabbed the gold." - Noah Lyles speaking to the BBC
Lyles powers home to victory
While Lyles was a strong pre-race favourite, the final did not quite go according to the script.
Gemili flew out of blocks just outside him in lane six and the Briton led coming off the bend.
But Lyles showed athletics composure beyond his years, staying relaxed and powering home to take a comfortable win in the end.
De Grasse again proved that he is back to his best with silver to match his Olympic silver from Rio 2016 with Quinonez passing a tired Gemili in the closing metres to claim his first medal in global competition.
Comparisons with Usain Bolt have been frequent since Lyles emerged as a hot prospect last season, but he has achieved something the big Jamaican did not in winning gold at his first World Championships.
Bolt took silver in the 200m behind Tyson Gay in 2007 before winning four consecutive 200m titles.
He told BBC afterwards, "There's so many times I've thought in my brain that, 'I'm going to be the world champion this year.' I've been saying it since the season started.
"Everyday I would go back home from practice, hitting my car window to the music like, 'I'm going to be world champion this year!'"
Australia's Kelsey-Lee Barber took the other title on the night, winning the women's javelin in the sixth and final round.
Men's 200m world champions
2019 Noah Lyles 19.83s
2017 Ramil Guliyev (TUR) 20.09s
2015 Usain Bolt (JAM) 19.55s
2013 Usain Bolt (JAM) 19.66s
2011 Usain Bolt (JAM) 19.40s
2009 Usain Bolt (JAM) 19.19s WR
2007 Tyson Gay (USA) 19.76s
2005 Justin Gatlin (USA) 20.04s
2003 John Capel (USA) 20.30s
2001 Konstantinos Kenteris (GRE) 20.04s
1999 Maurice Greene (USA) 19.90s
1997 Ato Boldon (TRI) 20.03s
1995 Michael Johnson (USA) 19.79s
1993 Frankie Fredericks (NAM) 19.85s
1991 Michael Johnson (USA) 20.01s
1987 Calvin Smith (USA) 20.16s
1983 Calvin Smith (USA) 20.14s