Asenathi Jim and Roger Hudson achieved a first-ever 470 World Championship race victory ©ISAF/Facebook

South Africa's Asenathi Jim and Roger Hudson gained a historic race victory today to jump to first overall at the halfway point of the 470 World Championships in San Isidro in Argentina.

The pair produced a superb tactical move to pass German rivals Ferdinand Gerz and Oliver Szymanksi to win race five and improve upon their 11th place finish in the opening race of the day.

It marked a first ever World Championships race win for the recently crowned African champions.

They now sit first overall after five out of 10 races on 21 points with Spain's Onan Barreiros and Juan Curbelo, who finished fourth in the day's opening race before slumping to a discarded 20th in the second.

Anton Dahlberg and Fredrik Bergstrom of Sweden are third on 27 points.

"It is a great feeling to actually have a race win at a World Championships, really amazing," said Jim.

"We seem to have a bit of pace but you know it was really tough to make any good moves in the fleet, because the wind was all over the show.

"It was interesting, as we bailed out of situations when we were deep."

Action at the 470 World Championships in San Isidro in Argentina ©ISAF/Facebook
Action at the 470 World Championships in San Isidro in Argentina ©ISAF/Facebook

Defending world champions Lara Vadlau and Jola Ogar of Austria showed ominous form in the corresponding women's event, gaining their first win of the regatta in race four to move up to second overall.

French rivals Camille Lecointre and Helene Defrance pushed them all the way to the line before having to settle for second.

It proved enough for them to move into a narrow two point lead at the end of the day on eight points, however.

Dutch rivals Afrodite Kyranakou and Anneloes van Veen of The Netherlands lie third.

This came as conditions remain difficult, particularly due to the presence of floating camelote plants which have washed down the Parana River, meaning it is good preparation for August's Olympic regatta on Guanabara Bay, where water pollution and other obstacles in the water remain a major concern.

"It is difficult," added Ogar.

"But this is really good training before Rio, as Rio is also quite a difficult venue, with a lot of things going on, like here.

"You have to be the smartest one and we are getting better every day, its nice."

Three more days of racing are due to take place before action concludes on Saturday (February 27).