Easing up well before the line, she still had a few metres to spare over experienced Jamaican Juliet Campbell and looked to be rediscovering some of her best form, following the shock of losing to Ukrainian Zhanna Pintusevich-Block in Monday's 100m final.
In her absence - she decided not to attempt to regain her half-lap title after the euphoria of winning the big one - the real challenge looks set to come from Debbie Ferguson, of the Bahamas, who won her semi in 22.39secs, and US compatriot Kelli White, who eased up just behind in 22.54sec.
American Inger Miller, the reigning champion who has been struggling for form all summer, was eliminated in fourth place behind them.
Hicham El Guerrouj, seeking a hat-trick of world 1,500m titles and attempting to erase the memory of his Olympic letdown, strolled into the semis as heat winner in 3mins 36.97secs.
But way behind him in eighth place British champion John Mayock, whose confidence and form seemed to have been knocked by a little barging match with Irishman James Nolan just before the bell, had an anxious wait before learning that he had scraped in as a fast loser in 3:39.24.
Shaftesbury Barnet's Tony Whiteman made easier work of qualifying, finishing a leisurely sixth, but major championship debutant Andrew Graffin, of Tonbridge, looked out of his depth, trailing home 10th.
