A race win to the previously fifth-placed Murray O'Brien has slingshot him into contention for the 2020 Sabre National Championship, as an uncharacteristically fluky day in Wallaroo shook things up at the top of the table.

The McCrae Yacht Club sailor had a great race yesterday, which saw him benefit from a massive right-hand shift up the first windward leg to lead from the first mark right through to the finish.

Meanwhile, those caught on the left side of the course were punished big time, of which included regatta leader and O'Brien's training partner, Alan Riley also from McCrae.

Riley said that while he was caught on the wrong side of the course and was buried in the fleet at the first mark, he was happy with how he was able to work his way back and salvage a sixth place.

But there were a number of sailors that weren't so lucky with the fourth and fifth-placed South Australians Craig McPhee and Ryan Kelly registering less than favourable results, with 11th and 15th respectively.

Unfortunately only one race was able to be sailed yesterday due to what was left of the hot northerly wind becoming marginal and fluky, with the windward mark-laying boat recording swings of more than 60 degrees while trying to set a course for the second race.

This has opened the doors for the second-placed Scott Olsen from Western Australia, and the now third-placed Murray O'Brien, who are one and seven points respectively behind Riley.

But with the drop coming into play in the next race, all of these guys will be looking to maintain consistent results to ensure they're in the mix at the pointy end of the regatta.

Further along in the fleet, Lauren Keil in Sweet Disposition sits in the lead in the female division, with the girls of the Sabre fleet showing strong numbers at this event, while the battle is also on in the other age divisions, with the grand master title still up in the air.

Today's weather is expected to be windy, with the race committee looking to get three races in to get back on schedule.

Keep up to date with all the action via the Down Under Sail social media platforms, as well as via www.downundersail.com

This event could not be possible without the support of the Copper Coast Council, as well as Ronstan.