Jamaican sprint star Usain Bolt qualified fastest for the 200m semi-finals on Friday as he attempts to put the misery of his world championships 100m disqualification behind him.

World record holder Bolt showed no signs of nerves as he prepared for the first race of his title defence, wowing a frenzied crowd - a far cry from the distraught figure whose 100m dreams were left in tatters by a false start.

At a packed Daegu stadium, with many seats filled for the morning session by schoolchildren, Bolt played the entertainer, goofing at the television cameras, showing the 'V' for victory, preening his hair and striking his trademark lightning bolt pose.

The reigning world and Olympic 200m champion, wearing yellow spikes and loose singlet over black shorts, clocked 20.30sec and never looked in danger after an impeccable start.

He was cautious off the blocks, registering the second slowest reaction time in a field of 53 runners but was soon into his stride and eased to victory in his heat, with several glances over his shoulder at the chasing athletes.

Bolt, who admits he is not in world record shape this season (his world record is 19.19sec), had insisted he would not dwell on the disappointment of his 100m disqualification.

The 25-year-old Jamaican, quickest in the world over the 200m this season with a run of 19.86sec in Oslo, whisked himself past journalists after the race with thumbs upturned.

European champion Christophe Lemaitre and American Walter Dix, 100m silver medallist in Daegu, also coasted through their heats along with Jaysuma Saidy Ndure of Norway and Berlin silver medallist Alonso Edward of Panama.

"I'll show you," a buoyant Dix said when asked whether he could beat Bolt.

"I felt relaxed running out from the blocks. I just wanted to make sure I came out clean. I feel that this year, the 200m is my stronger event and I'll definitely go for gold here.

"I'm not sure about how ready Usain is. This time it will not be as easy for him as in past years."

Lemaitre said: "This was an excellent race. I did a great curve. I did not outdo myself and I'm still very relaxed. But now I really need a good rest. Unlike the 100m, the 200m is a very exhausting event."

Other qualifiers for Friday evening's semi-finals included Jamaican Nickel Ashmeade, the 2008 world junior silver medallist, and 2003 100m world champion Kim Collins, who won bronze in the 100m in Daegu.

Australian Olympic silver medallist Sally Pearson (12.53sec) topped the timings in the women's 100m hurdles with Australia still searching for their first medal of any colour in South Korea.

American Kellie Wells also impressed but defending champion Brigitte Foster-Hylton of Jamaica scraped into the semi-finals.

Friday's evening session will see America's Allyson Felix go for a unique fourth consecutive 200m title but she faces a stiff test from US team-mate Carmelita Jeter, the newly crowned 100m champion, and Olympic gold medallist Veronica Campbell-Brown.

Kenyan defending champion Vivian Cheruiyot will bid to add the 5,000m title to the 10,000m crown she won on the first night of action at the worlds.

There are also finals in the men's shot put and long jump, the women's javelin and the 4x400m men's relay and South African defending champion Caster Semenya goes in the 800m women's semi-finals eyeing a berth in Sunday's final.