Berlin - "Six personal bests out of 10 events, 14th in the world, and a new national record - who could be unhappy with that?" said Willem Coertzen after the gruelling two day Decathlon at the World Athletics championship in Berlin.

Coertzen was on fire from the first event which saw the 26-year-old set a new season and personal best of 14.26sec in the 110m high hurdles. This shaved 0.07sec from his previous mark and earned 941 points ranking him 14th after six events. It was a trend he would maintain throughout the day.

A second round throw in the discus landed on 42.40m adding 5cm to his personal record. Even the 32-degree heat of Berlin's afternoon sun could not stop the UK-based teacher who opened his pole vault at four metres, skipped to 4.2, faltered with three attempts at 4.3 but then went on to go clear at 4.6 metres, 15cm higher than his previous best.

The roll continued in the javelin with a first throw of 65.46 eclipsing another best by 14cm and putting the South African on 7 418 points for 14th position going into the final 1500m race.

Taking a conservative start, Coertzen gradually moved through the field, passing the 800 mark in 2min28. Moving through to seventh in his heat, he pushed with 200m to go in the hope of earning the fifth and final personal best but five hours in the sun for the pole vault had drained his legs which could only carry him across the line in 4min32.57.

Those valuable 728 points took the two-day total to 8146 and the new national record.

"When I started in the 1500m, I could just feel the day's effort in my legs."

In Thursday morning's 800m first round Mbulaeni Mulaudzi and Sudan's Abubaker Kaki controlled the first heat keeping the field at bay and going through 400 in 53.13sec. With 250m to go the pair pushed for the line with the South African having the edge in 1min46.40.

Samson Ngoepe finished fourth in 1min46.54 and qualified for Friday's semi-finals as the first of the three fastest losers.

It was South Africa's most successful day of the championships so far.

"Everyone's motivation is up - that's why we are running so hard now," said Ngoepe of the team's reaction to Caster Semenya's golden 800m race on Wednesday night.

The country will hope the 800m duo maintain the motivation level on Friday night when Mulaudzi and Ngoepe take on perennial competitors Yusef Kamel of Burundi, and Russian Yuriy Borzakovskiy.

The Athens silver medalist will need to be at his tactical best to keep out of trouble and progress into Sunday night's final.

Long jumper Godfrey Khotso Mokoena took the positive form into the evening session, out-leaping the automatic qualifying mark of 8.15 metres with his second attempt.

After opening with a no-jump the 24 year old hit form reaching out to 8.29 metres which placed him third best of the qualifiers.

Most of the usual suspects will join Mokoena in tomorrow's final, with American comeback kid Dwight Phillips topping the list following a first trial jump of 8.44 metres.

Britain's Greg Rutherford set a national record of 8.3 metres and defending World and Olympic Champion Irving Saladino's 8.16 closed the qualifiers. - Sapa