Record-breaker Lavreysen dominates cycling worlds
Britain's Kieran Reilly earlier claimed the hosts' first gold of the championships winning the BMX Freestyle Park title.
Lavreysen, 26, was in imperious form as he destroyed the field, beating Trinidad & Tobago's Nicholas Paul in the final, to become the first sprinter in history to win five world championship titles in a row since the start of the professional era in 1992.
Lavreysen now has 13 world titles in total and will be the overwhelming favourite to win three gold medals next year at the Paris Olympic Games.
The two-time Tokyo Olympic champion, who came to the track after starting out in BMX, now has five titles in individual competition, five in team sprint, where the Netherlands reclaimed their crown on Friday, and three in keirin, another Olympic discipline.
European champion Reilly, meanwhile, had a spectacular run to finish ahead of Olympic champion Logan Martin of Australia in the final of the BMX Freestyle Park competition.
Martin, the last man to go after the competition resumed following a rain-delay, came up half a point short of Reilly's winning score of 95.80.
"It's the next level," said a jubilant Reilly.
"This is the biggest competition in the world outside the Olympics and this is the perfect stepping stone for me.
"I won the Euros a couple of months ago and to have those two jerseys at the same time shows the hard work is paying off."
Having laid down a solid first run, Reilly landed everything he attempted in the second.
"That was pure and utter relief for me," said Reilly.
"It's not as often as you'd like that you come off a course knowing you've done everything.
"To be one of the few guys still doing the double flair in competition, it's such a high-risk trick and it's taking that risk at the end of the run.
"I could have thrown it all away with that one trick but I'm glad I had that belief in myself and that it paid off."
American Nick Bruce finished third just ahead of former champion Rimu Nakamura of Japan.