The Australian made up for finishing second in the opening stage with impressive climbing and then sprinting in Stirling
His seventh success in his home tour, and still at the youthful age of 23, this was one of his most admirable wins to date, given that the route seemed to favour punchy climbers, as per previous years when the race has used an identical finish.
But Ewan managed to navigate the final shallow eight kilometre climb and beat Impey and Jay McCarthy (Bora-Hansgrohe) at the finish. It means that Ewan now inherits the ochre leader's jersey from stage one winner André Greipel, who had sprinted to victory in Lyndoch a day earlier.
How it unfolded
The second stage of this year's race started in Unley - a stage host for the 17th time - and finished in nearby Stirling in the Adelaide Hills, with the route heading north and then south before undertaking three laps of a finishing circuit that finished with a gradual eight kilometre ascent.
Yesterday's three breakaway riders - Will Clarke (EF Education First-Drapac), Scott Bowden (University of South Australia) and Nicholas Dlamini (Dimension Data) - worked their way into the escape group yet again from the off, joined by Spaniard Jaime Castrillo of Movistar.
Dlamini, a neo-pro, only had one thing on his mind: retaining and extending his lead in the King of the Mountains classification, which he did with relative ease, collecting the 10 points at the first KOM. Job done, the South African retreated back to the peloton.
The trio's lead was allowed to stretch out to over six minutes but after 78km of racing, and after Clarke had taken the second intermediate sprint and bonus seconds to elevate him into the race's virtual leader, both he and Bowden started to slip back into the peloton, leaving Castrillo as the sole leader.
The reigning Spanish U23 time trial champion, Castrillo managed to keep a lead of around three minutes for a lengthy period, but he was caught with less than 14km to go, the general classification and sprinting teams both sighting glory.
Greipel was to prove the parcour's first casualty, but Ewan (Mitchelton-Scott) and Peter Sagan (Bora-Hansgrohe) managed to keep pace as the ascent reached a short section of downhill before the final short climb.
As the flamme rouge approached, the peloton's size reduced to around 50 riders, with GC and sprinters present.
Robert Gesink (LottoNL-Jumbo) aimed to avoid the sprint by launching a move in the final 500m, but he wasn't able to build any lead.
When Sagan opened up his sprint, Ewan was alert and quick to pounce on the world champion's back wheel, following him intently until the Slovakian swung to the right, gifting Ewan space through the middle.
Ewan made the most of the open road and, in his trademark low sprinting position, he reached for the line, holding off the challenge of Sagan's colleague Jay McCarthy and Impey, who had impressively begun his sprint before Sagan's.
The third stage should also see a sprinter triumph as the race departs from Glenelg and concludes in Victor Harbor.
Tour Down Under 2018, stage two: Unley to Stirling, 148km
1. Caleb Ewan (Aus) Mitchelton-Scott, in 4-03-55
2. Daryl Impey (Rsa) Mitchelton-Scott
3. Jay McCarthy (Aus) Bora-Hansgrohe
4. Peter Sagan (Slo) Bora-Hansgrohe
5. Nathan Haas (Aus) Katusha-Alpecin
6. Elia Viviani (Ita) Quick-Step Floors
7. Gorka Izagirre (Esp) Bahrain-Merida
8. Domenico Pozzovivo (Ita) Bahrain-Merida
9. Luis Leon Sanchez (Esp) Astana
10. Carlos Barbero (Esp) Movistar, all same time
General classification after stage two
1. Caleb Ewan (Aus) Mitchelton-Scott, in 7-54-00
2. Daryl Impey (Rsa) Mitchelton-Scott, at 10 secs
3. Peter Sagan (Slo) Bora-Hansgrohe, at 12 secs
4. Jay McCarthy (Aus) Bora-Hansgrohe
5. Nathan Haas (Aus) Katusha-Alpecin, at 15 secs
6. Jhonatan Restrepo (Col) Katusha-Alpecin
7. Elia Viviani (Ita) Quick-Step Floors, at 16 secs
8. Simone Consonni (Ita) UAE-Team Emirates
9. Carlos Barbero (Esp) Movistar
10. Anthony Roux (France) FDJ, all at same time
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