In cold weather, rain and strong wind, Foster's Andrew and Warren Keegan battled a field of over 300 competitors at the Australian Championships on the weekend.

The race, which is held across the southern coastline of Sydney Harbour, saw competitors racing in pairs swimming and running continuously over a undulating 17 kilometre course.

This course included 12 swim legs totaling 3km of swimming and 13 runs totaling 14km of running.

Early on in the race, returning Australian SwimRun champion, Andrew Reid and his partner, professional triathlete Kieran Roache, took to the lead in a dominant fashion. Behind them saw the Keegan brothers engage in an epic battle with five other pairs at the front of the field.

The teams raced tightly with positions changing back and forth over the entire course with the duos of Shields and Cross, Jenkins and Campbell, Grueninger and Juncal and McMaster and Meagher exercising their strength on the run legs with the Keegan brothers regaining ascendancy in the swim legs with great turn of pace.

It all came down to the final two legs, a run across Rose Bay beach and a short swim around the western corner to the finishing chute.

The duo of Shields and Cross had by that stage secured a well deserved second place behind the dominant winners of Reid and Roche.

Behind them, four teams sprinted to the line.

"I knew if we stayed in close proximity to the teams up ahead going into the final run and swim legs we had a chance to beat them but it was always going to very tough,” Andrew said of the race.

"By that stage I was suffering leg cramps and I had also sustained a hand injury after hitting a shark-net pillion in a swim leg but we just had to keep on goin.”

And it was a tight finish indeed, with third to sixth place all finishing within a minute of each other after two hours of competitive swim run racing.

In the end the Keegan brothers were able to reach the line first by just 10 seconds and get the final spot of the podium.

"It was a tough race but we had a whole lot of fun racing alongside not only each other but against some quite talented opposition. It was also pleasing to come away with a great result" Warren said post race.

This was the first time the Forster brothers had competed in a swim run race and the Australian Championship but they look forward to taking part in future races.

The sport of SwimRun has experienced rising popularity across the globe with new events starting up every year and all culminating with the annual SwimRun World Championships held in Sweden.