Great Britain's Siobhan-Marie O'Connor has failed to grab a spot in tomorrow's 200m freestyle final at the World Championships, despite swimming a personal best time of 1:57.30.
The 19-year-old, who won bronze in yesterday's 200m individual medley, surged ahead in the first 50m of the semi-final, but dropped to third at the turn, with reigning champion Missy Franklin edging in front at the halfway point.
USA's Katie Ledecky, who broke a world record in her 1500m freestyle final victory earlier in the session, lagged behind in the initial stages of the race, but managed to finish third.
In the first semi-final, Italy's Federica Pellegrini, who is the world record holder in this event, impressed by hitting the wall in 1:56.23 ahead of Hungary's Katinka Hosszu.
Pellegrini heads into tomorrow's final as the fastest in the field, with Franklin second quickest following a time of 1:56.37.
O'Connor finished 10th overall.
