Korahubsh Itaa the prerace favourite to win the girls' 2000 steeplechase final came up trumps - but the Ethiopian was challenged to the limit by Kenya's Lucia Muangi in a thrilling five laps encounter.
Their lively competitiveness over the final circuit after a very swift open kilometre of 3:03.27 followed by another of 3:08.56, saw Itaa pushed to a new World Youth record of 6:11.83.
Every Ethiopia versus Kenya encounter distance running is normally exciting and this proved no difference, Itaa alongside her teammate Halima Hassen, being made to fight ever metre of the way by Muangi and compatriot Beatrice Kibor.
Kibor whose early pace split up the 12 strong field, was the first to wilt when Muangi put her foot on the gas pedal with two laps remaining to lead around the penultimate circuit.
Itaa a few strides after the bell hit the front, but Muangi covered the break as she did when Itaa who set a world 3000 steeplechase best in Spain last month, again tried to break her down the backstraight.
With neither athlete displaying any real technique over the barriers, it was nail biting action until Itaa coming off the last, dashed to the line for the narrowest of victories.
Muangi who was a tiny 0.07sec behind Itaa, also beat the previous world mark of 6:21.78 which Romanian Catalina Oprea achieved in Tampere, Finland in 2003, as did third finisher Hassen who clocked 6:16.83.
James takes gold in 400; back in the 200 tomorrow
Kirani James with a new Championship 400m record of 45.24 was immediately labelled "the next Usain Bolt" after speeding around the Sud Tyrol track in a time which was faster than Jamaica's Olympic 100m and 200m champion achieved at his age.
It may be premature to label the 16-year-old Grenadian who smashed the time of 46.10 Sudanese Nagmeldin Ali Abubakr set when winning title six years ago in Sherbrooke with that accolade yet, given Bolt never really turned his attention to it when a youth.
James the 2007 runner up however is undoubtedly a gifted talent - in the morning session he posted the fastest 200m qualifier of 21.18 - then returned to roar to what looks likely to be the first of the two gold medals he is aiming for.
Powering down the back straight his lanky strides had already drawn him well clear by the halfway point of Joshua Mance, Awadelkarim Elyas and Nathan Wake, who were battling for the other two medals.
Mance got clear, the American clocking a PB 46.22, while Elyas from the Sudan ran 46.22 his fastest of the season to edge Great Britain's Wake by just 0.05sec in 47.15.
"I wanted to set a World Youth record and I am disappointed to have missed that," said James just shy of the USA's Obea Moore's fastest ever time of 45.14 set in 1995.
Eutsey sets year lead to take girls’ race
Ebony Eutsey became the first USA winner of the 400m title last claimed by Natasha Hastings in Sherbrooke in 2003 with a confident display where she was always ahead of her opponents.
Eutsey who came to the championships holding the fastest time in the world this year of 52.07, may have risen second from the blocks, but quickly getting into her strode powered to the front of the field.
The American had the gold medal in her pocket entering the home straight, but the race for silver was a lot closer between Michelle Brown and Sandra Wagner.
The winner's teammate stretched almost on the line to get the decision by 0.08 as Wagner confirmed herself as European Number One with another personal best of 53.52.
Eutsey whose idol is Allyson Felix and looking towards the London 2012 Olympic Games, said: "I was very nervous all day long but now I feel great.
"I know that I am in good shape and will continue to train to qualify for the next Olympics."
US keeps stranglehold in high hurdles
Dale Morgan becoming the fourth successive USA winner of the 110m Hurdles title was made to fight every inch of the way by Jack Meredith the Briton who had dominated the earlier rounds.
Their neck-and-neck confrontation down the home straight brought the packed stadium crowd to its feet as neither wilted until Morgan edged ahead coming off the final hurdle to win in 13.28.
Meredith who had posted a World leader and PB of 13.42 in his semi, improved to 13.33 but just didn't have the speed to pass Morgan who narrowly missed the World Youth best set by fellow countryman Wayne Davis two years ago by 0.10sec.
Canada's Gregoery MacNeill added to Aaron Brown's 100m silver medal taking third place in 13.51.
Hammer gold goes to China
Hongqui Chen not in this year's world top 10 when arriving in Bressanone, clinched the gold medal with his first attempt - a World leading mark and best ever throw of 74.93 - then immediately went into limbo for the next two rounds.
The Chinese athlete, whose previous PB was 73.63 and achieved his best this summer of 71.32 the furthest in the qualifying rounds, then had two no throws.
Chen not surprisingly after his brilliant start was risking everything to get in another really big effort and it finally came in the final round, but was 89 centimetres short of his winner.
"I am overjoyed, this was my best performance ever," said Chen, whose potential was discovered when talent scouts came to his home on the island of Hainan and recruited him for China's national team.
Behind him there was a tight battle for the two other medals and Tomas Kruziak seemed to have it sewn up with his opener of 72.17.
However the Slovak had to settle for the bronze medal after Suhrob Khodjaev of Tajikistan in the final round improved his lifetime best by four metres to 73.29.
Alessia Trost of Italy brought the loudest cheer of the championships so far from a partisan Sud Tyrol crowd when winning the high jump with a height of 1.87.
That was just a centimetre lower than the world leader for the year which she achieved in Pordenone in mid-May and marked her out as the pre-event favourite.
Trost who opened her account with a safety jump at 1.65 produced only one failure at 1.79, to win the gold medal ahead of Mariya Kuchina and Amy Pejkovic.
The Russian and Australian jumpers after a tense afternoon shared the same height with personal bests of 1.85.
Russia’s first medal
Russia's first gold medal came in one of the country's richest events the triple jump where Yana Borodina produced an exceptional performance.
Borodina getting her technique perfect down the runway flew out to a distance of 13.63 with her opening attempt which constituted a new world leader for the year and an improvement of 33cm on her personal best.
It wasn't an easy victory, indeed she suffered some tense moments as runner-up Lina Deng of China produced four leaps over 13m, her best of 13.57 in round three, keeping the pressure on the Russian.
Uzbekistan's Valeriya Kanatova who came into the final as world leader with 13.55 had to settle for the bronze medal with a distance 10cm shy of that mark.
Brave effort pays off for Pohle
Hagen Pohle totally motivated and more importantly maintaining his self belief smashed the 10 kilometres Walk Championship record with a time of 41:35.99.
The German showing great concentration and leading from start to finish produced a time which bettered the 41:49.91 Russia's Stanislav Emelyanov achieved in Ostrava two years ago.
Pohle who went through the half distance in 20:43.37 won ahead of Russia's Dementiy Cheparev who clocked a personal best of 41:53.76 and Ihor Lyashchenko.
The Ukrainian bronze medallist who topped this year's rankings coming into the competition with a time of 42:50.16 was much faster than that mark set a month ago in Vinnitsa recording his fastest ever of 42:01.90.
Heptathlon First Day
Great Britain's Katarina Thompson tipped to medal in the Heptathlon made a brilliant start, setting personal bests in the 100m Hurdles of 14.17sec and High Jump with 1.82m, to lead at the end of the morning session.
Then in the afternoon she kept the top placing, with a Shot Put effort of exactly 10 metres and then rounding off the opening day's action with a personal 200m best of 24.34.
That gave Thompson a tally of 3434 points and a lead of 64pts from Laura Ikauniece of Latvia with Germany's Kira Biesenbach lying third with a total of 3301pts.
800m semi final
Ciara Mageean set the standard for what is likely to be a closely contested 800m final on Sunday when powering to the fastest semi final time of the day of 2:05.66 dragging British runner-up Rowena Cole to a lifetime best of 2:05.80.
Ukrainian Olha Lyakhova easily took the next round in 2:06.32 from Alawia Maki Andal of Sudan (2:07.99) while Kenya's Cherono Koech running a PB of 205.71 won the last semi in a PB 2:05.71 from current world leader Cuba's Rose Mary Almanza (2:06.17).
That race also saw Tizita Bogale and Viktoria Gyurkes go through as fastest losers, the Ethiopian and Hungarian clocking 2:06.31 and 2:08.13.
There were 10 automatic qualifiers for the boys’ Pole Vault final, all of them confidently clearing the automatic qualifying standard 4.85.
Germany's Carl Paech who has a personal best of 5.20m needed only one attempt to attain the required height while Daniel Clemens his teammate and world leader with 5.35, had a first time success at 4.70 before also making it with one jump at the requisite height.
Four contestants achieved the automatic discus qualifier of 47 metres needing only one attempt the biggest effort coming from 2009 world leader Alex Collatz who threw 49.43.
Hot on the American's heels were China's LI Shanshan who lies second in the rankings and recorded 49.14 with Lena Urbaniak winner of the shot title producing an effort of 48.00 and Viktoriya Klochko 47.12.
David Martin for the IAAF