Entering the finale with an eight-second general classification buffer over Patrick Bevin (Avanti Racing Team), the intermediate time bonus guaranteed Ewan (Orica-GreenEDGE) his first overall victory in a UCI stage race.
The stage was won by RTS-Santic Racing Team's Tino Thomel followed by Bevin and Drapac's Wouter Wippert. Ewan's fifth place was enough to secure the overall, points and young rider classifications.
“It’s obviously a lot different to racing in Europe,” Ewan said. “Although the teams are of a lower level it’s harder for us to control the race with only six guys because everyone was looking at us to do something.”
“With no mountain stages, every day you were going for the sprint and that adds up over the week to make it pretty stressful but we always had it under control.”
The out-and-back final stage, ending in Seoul's Olympic Park with a 5km circuit was short 65km but still contained enough variables for a tight finish.
Two intermediate sprints offered three seconds of time bonuses apiece, while the final sprint promised a 10 second time bonus for the stage winner.
Travis Meyer (Drapac), Lee Kisuk (Seoul Cycling Team), Seo Joonyong (KSPO) and Kohei Uchima (Bridgestone Anchor) made the break and set about crafting a lead of one minute 30 seconds on the peloton.
Orica-GreenEDGE and Avanti Racing Team allowed the four-man break to pass through the first intermediate sprint and sweep up the time bonuses but gave them no such latitude on the second
While the break was up the road contesting the first intermediate sprint, Ewan was forced to change to a spare bike but quickly bridged back to the peloton, which had clawed back the lead group's advantage to 30 seconds.
Ewan then contested and won the second intermediate sprint with teammate Adam Blythe on his wheel to grab the valuable seconds on offer. Bevin took third as Ewan stretched his overall advantage to ten seconds.
Even in the unlikely event of a draw on time at the finish, Ewan had the race in the bag on a stage win count back.
"The team wanted me to get at least one stage win so to come away with four and also the young rider, GC and sprint classifications is a massive bonus," Ewan said.
“It was a nice surprise having (my parents) here, and I’m glad I could pull off the overall for them. It’s really nice."
"The main thing was I got to work with the guys and we really got to work on our lead-out. That was the main goal coming here, to really gel with the team, and they were awesome this week.
“I’m still a fan of cycling, so to have the Orica-GreenEDGE team riding in front of me, helping me win these races, is really special. I’d still like to get a few more wins and hopefully bigger wins."
1 Caleb Ewan (AUS) Orica-GreenEDGE 29hr 53min 28sec
2 Patrick Bevin (NZL) Avanti Racing Team 0:00:04
3 Adam Blythe (GBR) Orica-GreenEDGE 0:00:44