Great Britain's Christine Ohuruogu has booked her spot in the final of the women's 400m at the World Athletics Championships in Beijing.
The reigning champion, who is bidding for a third world title, powered through on the home straight to win the second heat at the Bird's Nest Stadium, where she claimed gold at the 2008 Olympics.
The 31-year-old finished in a season's best time of 50.16s, 0.16s ahead of Jamaica's Stephenie Ann McPherson.
There was less joy for Ohuruogo's compatriot Anyika Onuora, however, as she tired on the home straight to finish fifth, although her time of 50.87s was a big personal best.
USA's Allyson Felix set the fastest qualifying time for the final with a 49.89s, while Shericka Jackson's time of 50.03s was also enough to secure her spot in the showpiece.
Elsewhere, Shaunae Miller of the Bahamas eased to victory in the first heat with a time of 50.12s, while Christine Day came in second to also book her place in Thursday's final.
Novlene Williams-Mills and Phyllis Francis complete the lineup for the final having qualified as the fastest losers.
Barney Corkhill
