Daryl Impey (Mitchelton–Scott) became the first South African rider to win the race overall, after edging out BMC Racing Team's Richie Porte on countback after both riders completed the course in the same time.[3] Porte won on Willunga Hill for the fifth year in succession, but Impey finished eight seconds in arrears in second position, which was enough to take the ochre jersey.[4] The podium placings were completed by another former winner, Tom-Jelte Slagter of Team Dimension Data, who finished third on Willunga Hill, taking four bonus seconds that put him ahead of the four other competitors that he had finished with; Slagter finished 16 seconds down on Impey overall.[5]
In the race's other classifications,[6] world champion Peter Sagan (Bora–Hansgrohe) won the sprints classification, taking five top-five stage finishes during the event, including a stage win into Uraidla. Team Dimension Data's Nicholas Dlamini led the mountains classification from start to finish, while Egan Bernal of Team Sky took the young rider classification in his first start for the team, finishing sixth overall. The teams classification was won by Bahrain–Merida, who placed Gorka Izagirre in the top-ten overall.
As the Tour Down Under was a UCI World Tour event, all eighteen UCI WorldTeams were invited automatically and obliged to enter a team in the race.[7] One other team was given a wildcard entry into the race: UniSA–Australia.[8] Each team was due to enter seven riders, for a total of 133 participants. However, Lotto–Soudal withdrew Bjorg Lambrecht from the race following an error with the UCI's anti-doping procedures,[9] while Team Sky lost Kristoffer Halvorsen following a crash in the closing metres of the People's Choice Classic, which resulted in a fractured hand.[10] As a result, 131 riders started the race.[11]
The opening stage started in Port Adelaide, which hosted the race for the first time since the inaugural Tour Down Under in 1999.[19] The fifth stage finished with two climbs of Willunga Hill, which had been decisive in previous editions of the race. The final stage was another criterium around the centre of Adelaide.
After stage two, it was announced that the third stage would be shortened due to forecasted high temperatures. Two of the three finishing circuits around Victor Harbor were removed from the itinerary, reducing the racing to 120.5 km (75 mi).[20]
In the 2018 Tour Down Under, four different jerseys were awarded. For the general classification, calculated by adding each cyclist's finishing times on each stage, and allowing time bonuses for the first three finishers at intermediate sprints and at the finish of mass-start stages, the leader received an ochre jersey.[37] This classification was considered the most important of the 2018 Tour Down Under, and the winner of the classification was considered the winner of the race.
Additionally, there was a sprints classification, which awarded a green jersey,[37] a change from red in 2017. In the sprints classification, cyclists received points for finishing in the top 10 in a stage. For winning a stage, a rider earned 15 points, with one point fewer per place down to 6 points for 10th place.[38] Points towards the classification could also be accrued at intermediate sprint points during each stage; these intermediate sprints also offered bonus seconds towards the general classification. There was also a mountains classification, the leadership of which was marked by a white jersey with navy polka dots.[37] In the mountains classification, points were won by reaching the top of a climb before other cyclists, with more points available for the higher-categorised climbs.
The fourth jersey represented the young rider classification, marked by a white jersey.[37] This was decided in the same way as the general classification, but only riders born after 1 January 1994 were eligible to be ranked in the classification. There was also a classification for teams, in which the times of the best three cyclists per team on each stage were added together; the leading team at the end of the race was the team with the lowest total time.[37] In addition, there was a combativity award given after each stage to the rider(s) considered, by a jury, to have "instigated the most attacks, breakaways or assisted their teammates to the best advantage".[37]
^"Part 2: Road Races"(PDF). UCI.ch. Union Cycliste Internationale. 1 January 2018. p. 140. Retrieved 16 January 2018. 2.15.127: The UCI WorldTeam must take part with a team of competitive riders in UCI WorldTour events.