Five New Zealand crews are threatening the medals with a day to go at the ISAF Sailing World Cup event in Palma.
Best-placed are 49erFX skiff sailors Alexandra Maloney and Molly Meech who are in second place of 34 in the hotly contested fleet.
Overall leaders Nielson and Olsen from Denmark faltered on day five, blotting their zero points card with a 4th, 10th and 4th - while Maloney and Meech stepped up to open the day with a bullet followed by two second places.
They narrowed the gap to the leaders to eight points adrift and are eight points clear of the German sailors in third. The top eight boats race four stadium-style races to determine the medals.
Meanwhile, New Zealanders Sam Meech and Andy Maloney are both in the hunt for medals in the Laser fleet where the medal racing differs from that for the skiff sailors. Meech and Maloney are lying third and fourth locked on equal points at the end of the penultimate day. Tomorrow the top 10-placed Laser sailors will sail two medal races, each worth double points.
Australia's Tom Burton has a solid lead 16 points clear of the chasing pack featuring Fontes of Brazil on 31, Meech and Maloney both on 35 and Stipanovic with 41. Laser sailor Thomas Saunders has wrapped up his regatta in 15th overall.
In the Finn, Josh Junior and Andrew Murdoch improved their overall standing by one position on day five and head into their medal races lying sixth and seventh.
The top 10 sailors to sail two races, each worth double points. Just one point separates the two Kiwis, with Junior 14 points adrift of third place.
Men's 470 pair Paul Snow-Hansen and Daniel Willcox missed the cut for the men's double-handed medal races, by one point.
Cooler conditions are forecast for Palma tomorrow which is likely to return more wind to the race track.