The 10km run was flatter, but the four laps still featured the false flat on Queen Street. Still, Hewitt looked fresh as she broke the tape. Those following looked less so, including Sakimoto and fellow Japanese Mariko Adachi.
Hewitt waved to the crowd and had time for a quick kiss and photograph with boyfriend and coach Laurent Vidal of France, who was getting ready to start the men's elite race.
The victory was a great finish to a successful year for Hewitt, who earlier won back to back World Cup events in Beijing and Yokohama.
"My legs felt a little bit sore starting the run but I just tried to pace myself and managed to get away from the Japanese girl [Adachi] straight away so I just kept going and had a good win," Hewitt said.
Hewitt finished the first leg, the 1.5km swim, in good shape, coming into the first transition in seventh place.
A group of eight riders, including New Zealand Teresa Adam went away early and were never threatened, although three riders, including Great Britain's Vicky Holland found the pace too hot and dropped off.
"The first few laps we just tried really hard on the hills to get away and we ended up dropping a few girls and then we had a group of five for the second half of the race so that's how it worked out and it all came together," Hewitt said.
"I was attacking those hills but the Japanese riders were so strong. It was actually Sakimoto who came with me in Beijing and Teresa was great today. She was the first to help me on the bike ... we dropped a few after the first few laps so it was a good way to do it."
Hewitt led Adachi out of the bike/run transition and was never headed, though Adachi dropped back a place to her countrywoman Sakimoto.
Adam fell away on the run leg after her impressive efforts early in the race. She was second out of the water behind Adachi and her and Hewitt looked in a class of their own on the bike as the five riders, which included Italy's Alice Betto, headed for the run. Both New Zealanders pushed the pace at the front but Aucklander Adam fell away after the shoes were put on.
Fellow New Zealander Nicky Samuels also had a disappointing race after having a poor swim.
She said the legs deserted her on the bike and couldn't make up the gap to Hewitt's group.
"No one wanted to work and I didn't have the strength to go by myself," she said.
As for number one seed Hewitt, one of her biggest problems of the day was saluting the crowd in appropriate fashion.
"The whole of Queen Street was lined [with supporters]. That's why I took my sunglasses off on the last lap and I was smiling, but it's really hard to smile and race."
Andrea Hewitt (NZL) 2:14:11, 1; Tomoko Sakimoto (JPN) 2:15:09, 2; Mariko Adachi (JPN) 2:15:23, 3.