However, 47 per cent of the eligible voters said they either didn't know who they will vote for, refused to express their preference, or said they did not plan to vote.
The poll took into account that Wellington City uses the Single Transferable Voting (STV) system.
Under STV, voters are able to rank candidates in order of preference, rather than simply pick their most preferred candidate for each vacancy.
After various candidate preferences were accounted for in the poll, Eagle was on 51 per cent and Whanau on 49 per cent- signalling a very tight race.
If Eagle won the mayoralty, a byelection would be triggered for his vacant Rongotai seat.
He has been running a back-to-basics campaign, saying he will run the ruler over council spending, and promising to be an experienced pair of hands to steady the ship.
Eagle told Q+A host Jack Tame he wasn't taking anything for granted and was interested in how many people were unsure who they will vote for.
Asked why he wasn't further ahead considering his profile in Wellington, Eagle said people wanted to "look closely" before voting and there was still a long way to go.
"They want to get back to basics, they want a plan for the city, and they want to restore Wellington as the arts, events, and culinary capital. That's what they've told me and that's what I'm offering back."
Whanau has been campaigning on her ability to bring people together, pointing to her experience around the negotiating table with New Zealand First.
She told Tame she was excited by the poll results as a newcomer.
"I didn't have profile before I ran. I think the result is really exciting for me, I think it's a really strong indication that people are ready for change.
"But I can't be complacent. So what I'm saying is, if you're on the fence, come and meet me."
Foster has had just one term in the top job, after being a Wellington City councillor for nearly 30 years.
His 2019 win was unexpected and down to the wire. Foster claimed victory with a margin of just 62 votes over Labour mayor Justin Lester.
Foster's ensuing term as mayor has been difficult, his council accused of infighting and being dysfunctional.
On the campaign trail, Foster has been pitching to voters a list of projects that have got underway on his watch. He has claimed his council was working constructively in more recent times.
Asked why he was losing, Foster told Tame a lot of his campaign material had only been distributed in the past week.
He said he has steered the council through a tough time over the past three years.
"My pitch really is to say I've got things done that many previous councils didn't get done, and I need another three years to finish that job."