Noemi Zbaren confirmed her position as pre-event favourite after equalling her 2011 world 100m Hurdles leading time when the qualifying rounds of the seventh edition of the IAAF World Youth Championships got underway in Lille, France, on Wednesday (6) morning.
The 17-year-old Swiss starlet in the opening track event roared to a time of 13.31 which matched the previous leader she achieved almost three weeks earlier in Schweinfurt, Germany.
Zbaren's positive performance where her speedy display also matched the Swiss record she first achieved in May last year, saw her pull France's Christelle Vertueux to a personal best of 13.86 and clearly indicated she has the ability to run even quicker before the five day Championships conclude.
"I just wanted to test the track and I didn't think of a season's best in qualifying," said Zbaren bidding to become the first competitor from her country ever to win a medal at these Championships since their inception in 1999.
Trinity Wilson and Kendell Williams who finished first and second at last week's USA Youth Championships and rank in that order behind last year's Olympic Youth bronze medallist also progressed effortlessly with times of 13.59 and 13.60.
Kosencha makes dream 800m debut
Mohammed Aman who clinched the Youth Olympics 1000m title in Singapore made light work of winning his 800m when after following John Apolinario through the first lap he reserved his finishing speed for the final straight.
The Ethiopian and world leader - he clocked 1:45.74 in Montreuil-sous-Bois a month ago - was barely out of breath when crossing the line in 1:53.17 ahead of Morocco's Nader Belhanbel (1:53.44) with Denmark's Mihn Kyun Cho also qualifying for the next round with a PB 1:53.54.
Qatar's Hamza Driouch who finished behind Aman at the Youth Olympic made even lighter work of making Thursday night's semi-final when coasting to victory in 1:50.55 well clear of the host nation's Gaetan Manceaux ((1:52.30) with Nikolaus Franzmair of Austria running a lifetime fastest of 1:52.88.
However it was Kenya's 16-year-old Leonard Kosencha who posted the fastest time of the qualifiers when in his first ever electronically timed 800m race he cruised through the first 400 in 52.78 and moved to sixth on the 2011 World list with a time of 1:49.32.
Kipyegon, wearing shoes, sets 1500m best
His fellow countrywoman Faith Chepngetich Kipyegon, well remembered for winning the 2010 IAAF World Cross Country junior title running barefooted in Bydgodzcz, Poland, set a personal best of 4:16.95 to lead the 1500 qualifiers.
Kipyegon, determined to keep the title in Kenyan hands for a fourth successive Championships and follow in the footsteps of Nelly Ngeiywo's victory in Bressanone two years ago, looked comfortable as she outpaced Ethiopia's world leader Genet Tibieso by 0.73 with Great Britain's Georgia Peel third in 4:19.14.
The earlier heat saw Senbere Teferi of Ethiopia outstrip the field wining in 4:21.44 but the battle for second place was much livelier with five contenders straining at the leash for the remaining three spots in the final.
Sheila Chepngetich Keter (4:25.03), the USA's Hannah Meier (4:25.28) and Amy Laman of Australia (4:25.53) gained but Maya Rehberg and Shiho Takeda of Japan were rewarded for their fighting displays moving through as fastest losers and times of 4:25.70 and 4:25.89.
Gordon looks good, but so do her 400m rivals
Chrisann Gordon, currently the fastest 400 runner in the world with a time of 51.62, posted the quickest first round time of 53.52 but the Jamaican knows she will have no time for relaxing as all her main rivals also went through to tomorrow's semi finals with solid performances.
With six of the seven current world's quickest one lap athletes chasing the gold medal it promises to be one of the highlight events of these bi-annual Championships which has attracted a record 1375 participants representing 173 countries to Lille's Metropole Stadium.
Shaunae Miller the reigning World Junior title holder quickly dispersed her rivals winning her heat by almost three seconds in 54.39 with Youth Olympic gold and silver medallists, the USA's Robin Reynolds and Bianca Razor of Ukraine, producing sharp victories in 54.59 and 54.15.
Canada's Christian Brennan and Olivia James also made light work of going through recording 53.83 and 54.78 while Poland's Patrycja Wyciszkiewicz lowered her personal best by 0.61sec with 53.71 the second fastest of the rounds behind Gordon.
Oseto second fastest in 100 qualifiers
Kazuma Oseto the second fastest teenager in the world this summer over 100 and fastest entrant at the Championships with a time of 10.39, had to wait until the 12th and last heat of the competition before clinching his place in Thursday night's semi final.
The 16-year-old Japanese who set the second fastest mark of 10.65 of the day in a line up which attracted an unprecedented entry of 95 competitors, was headed by Australia's Hugh Donovan who lowered his PB by 0.08 to 10.60.
With just the first two guaranteed to progress and despite the cold weather during the preliminaries, there were some lively encounters although the competition will be even keener and faster with better conditions forecast in the next few days.
Dacres and Guo looking good for gold on the infield
World leader Fedric Dacres of Jamaica needed only one attempt to make it through to the discus final with a throw of 61.57m while Hungary's Janos Kaplar also bettered the required distance of 57.25m with a second round effort of 57.95m.
With the pair then content to watch as spectators they saw Columbia's Maurice Ortega unleash the biggest distance of the day, a personal best of 61.78m, while Gerhard De Beer from South Africa threw 59.45m.
The earlier round saw South Africa'a Jan-Louw Kotze who lies a place behind Dacres in the world rankings and Viktor Gardenkrans who is seventh, automatically make the cut throwing 57.95m and 57.47m in round 2 to make tonight's final.
The absence of Vadym Adamchuk who by a healthy margin tops the Long Jump rankings with 7.95m but has opted in Lille to contest only the Octathlon saw Spaniard Sergio Acera (with a wind assisted clearance) and Qing Lin the World Number 2 from China lead the qualifying groups both clearing 7.49m.
Russia's Semen Popov and Italy's Riccardo Pagan (after two fouled attempts) had leaps of 7.43m and a windy 7.39m which also moved them into Thursday evening's final after beating the qualifier of 7.35m.
Another world leader Tianin Guo seeking to become a third Chinese gold medallist also went into tonight's girls Shot Put final when transiting the qualifier of 14.00m with a first round put of 14.68m.
Germany's Katinka Urbaniak sister of 2009 champion Lena and Korea's Mina Lee - with a PB - did likewise throwing 14.24m and 14.22m. Group B saw Great Britain's Sophie McKinna (14.27m) also get automatic qualification with her final attempt as did New Zealander Sositina Hakeai of Sweden who threw 14.23m in round two.
Herashchenko hoping to emulate Kovalenko's Sherbrooke win
World High Jump Number One Iryna Herashchenko was one of nine contestants to clear 1.75m to make Friday's final, the rapid elimination of others in the 30 strong field not requiring the bar to be raised to the qualifing height of 1.80m.
Herashchenko, eager to emulate the victory of fellow Ukrainian Irina Kovalenko in Sherbrooke, Canada, eight years ago, was joined by third ranked Chanice Porter of Jamaica who also jumped 1.75m. But Australian Kaitlin Morgan who separates them in the rankings had a day to forget crashing out after a best of just 1.67m. So too did seventh ranked Daniellys Dutil from Cuba who although clearing 1.72m which earned three athletes a place in the final lost out on countback with more failed attempts.
Likhanov leads Octathlon after two rounds
Evgeniy Likhanov of Russia held the lead after the first two disciplines in the Octathlon with the eighth fastest 100 time in the morning session of 11.44 followed by a long jump PB clearance of 7.46m giving him a tally of 1690 points.
Australia's Jake Stein was 76 points behind in the eight event competition with 100m and Long Jump marks of 11.52 and a PB 7.22m. Sweden's Frederick Ekholm (1564) after a 11.51 sprint into a headwind of -2.4m/s rose from 12th to third with his long jump furthest of 7.00m also the best of his career.
David Martin for the IAAF