American Michelle Perry retained her world 100m hurdles title thanks to a superb fightback in the final stages.

Perry trailed both European champion Susanna Kallur and team-mate Virginia Powell with 40m to go but hit back to cross the line first in 12.46secs.

The 2003 winner Perdita Felicien had to settle for silver this time in 12.49 with Jamaica's Delloreen Ennis-London grabbing bronze in a personal best of 12.50.

Sweden's Kallur faded in the closing stages and despite running a PB of 12.51 could only finish fourth.

Powell was fifth in 12.55.

A delighted Perry said: "It was a close call. We waited for couple of minutes, I did not know who won. I was thinking am I second or third? Now I want to enjoy it.

"It was an extremely difficult race, I rate it in top three most difficult ones in my career. I kept talking to myself that I can win this race and defend my title and stayed calm."