The Lotto-Soudal rider triumphed in a sprint finish after a 135.8 kilometre ride from Woodside to Stirling.

He timed his dart to the line to perfection, after his team avoided a nasty crash which took out a number of contenders just 1.4km from the finish.

Britain's 2018 Vuelta a España champion Simon Yates, riding for Mitchelton-Scott, has suffered a knee injury, while Belgium's Ben Hermans, of Israel Start-Up Nation, is out of the race after fracturing his collarbone.

Italy's European road race champion Elia Viviani, riding for Cofidis Solutions Credits, was another to be caught up in the carnage.

Despite taking the race leader's ochre jersey, sprint specialist Ewan is not considered a contender for overall honours.

He has now won eight stages at the Tour Down Under, the opening leg of the International Cycling Union's World Tour season.

"I'm super happy with that win," said Ewan, whose time was 3 hours 27min 31sec.

"The boys did an absolutely perfect job today.

"They did everything I asked for and I got delivered to the line in a perfect position.

"When you take a win like that, you really can't do it on your own. 

"I said to them yesterday, 'if I'm going to win today's stage, it's a tough one so I need all the help I can get', and they really helped me all day and kept me in a good position which meant I could avoid the mess. 

"And that helped me in the end because I had good legs for the sprint."

Ewan's overall time is now 6:56.15, the same as Ireland's stage one winner Sam Bennett.

The Deceuninck-Quick-Step man finished 11th today, amid the pack and on the same time as Ewan, but the Australian leads the Tour overall on countback.

South Africa's back-to-back general classification winner Daryl Impey finished second in the stage and the Mitchelton–Scott cyclist is now third overall, just one second behind the top two.

The stage today went past land destroyed by Australia's bushfire crisis, and included 2,357 metres of climbing.

Tomorrow's stage three of six is a 131km climbing-friendly route from Unley to Paracombe.