Rowsell clocked a personal best 3:30.318 minutes over three kilometres to defeat the defending champion, the USA's Sarah Hammer.
“This has been a personal goal for me for a while, I just can’t believe I pulled it off and it means the world to me," Rowsell told British Cycling.
"I can’t believe I’ve done it, I can’t believe I went that quick.
“The team pursuit is obviously still the priority that’s what we train for and I’ll live and die for those girls.
"But it’s a really good chance for me to come here and do an individual event the day after the team pursuit, so we can prioritise the team pursuit."
Great Britain's Becky James saw the defence of her world sprint title ended in the quarter-finals by team-mate Jess Varnish, who she joined to win team sprint bronze on Wednesday.
Varnish will now face China's Zhong Tianshi in Saturday's semi-finals while Germany's Kristina Vogel takes on Lin Junhong in the other race.
Elsewhere, Ed Clancy ended the first day of the men’s omnium in sixth place after three of the six events.
- Sports & Recreation