World Athletics 2011: Oscar Pistorius through to semi-finals

Debate has raged this week on whether Pistorius should be allowed to compete

South African Oscar Pistorius qualified for the semi-finals of the 400m on his historic appearance at the World Championships in Daegu.

The first amputee athlete to race in the competition finished third in his heat in 45.39 seconds.

The four-time Paralympic champion, 24, finished behind winner Chris Brown, with Britain's Martyn Rooney second.

World and Olympic champion LaShawn Merritt of the United States qualified fastest in 44.35.

Merritt is making his first major championship appearance since returning from 21-month doping ban.

Pistorius, who has a personal best of 45.07, said: "I am tired, I need to cool down now, to relax, refocus and chat with my coach.

"I had a good race. I'm just pleased to be part of this sport, of this event.

"Being here has been a goal I have had for many years. I have worked extremely hard to be here.

"It has been phenomenal to run today. There has been a lot of pressure on the race, and there is a lot of work for Monday.

"I need to be as consistent as today."

There was disappointment for Britain in the 1500m as Lisa Dobriskey finished second last in her heat and went out.

The defending silver medallist appeared to stumble and lose ground with just under a lap to go and came home in four minutes 12.70 seconds.

Dobriskey, who has been struggling with a back injury, said: "I felt like I raced well and maintained my position but my legs did not seem to be there when they needed to be.

"With 300m to go I panicked a bit and pushed too hard and that was it. I don't know what happened. I thought I was coping well with it [the injury] but obviously not. I'm very disappointed."

Her British team-mate Hannah England ran slower and won her first round, producing a strong finish to cross the line in 4mins 13.45secs.

Another surprise exit was British record holder and World Championship medal hopeful Holly Bleasdale in pole vault qualifying.

The 19-year-old, who broke team-mate Kate Dennison's mark earlier this year with a clearance of 4.70m, failed to record a height.

The Preston athlete, making her major championship debut, failed her three attempts at 4.25m to crash out.

European and Commonwealth champion Andy Turner qualified comfortably for the semi-finals of the 110m hurdles.

The 30-year-old, who finished second behind China's former Olympic champion Liu Xiang in his heat, was joined in the next round by Will Sharman, but Lawrence Clarke went out.

Turner clocked 13.32 with Liu winning in 13.20.