And the home side lost four lineouts - four too many for Hansen's liking.
"It's just a start," Hansen said. "We've got a lot of work to do. They exposed us in a couple of areas. We didn't connect that well in our kick-chase so we'll work on that and try to fix that.
"They challenged us at lineout time and we challenged them. I thought both defensive lineouts were very good, we stole ball at crucial times from each other."
Hansen added: "Williams beat three people to get out of the 22 and once you do that then you're really scrambling, but in saying that I was really proud of our scrambling defence."
All of which will send Warren Gatland back to the drawing board in a bid to beat the odds and win back-to-back tests for the series. His starting locks George Kruis and Alan Wyn Jones are likely to come in for scrutiny and he must be considering starting Owen Farrell at second-five, with Johnny Sexton at No10, in order to create more finesse in the midfield.
For Hansen, the Lions' tactics at the breakdown surprised him a little, although he admitted this was was a calculated gamble.
"I thought they were reasonably non-abrasive at the breakdown," he said. "They allowed us to get the ball we needed to get by not putting numbers in because they wanted to get line speed... they wanted guys on their feet [in the line] rather than attack us at the breakdown.
"They might look at changing that so we'll have to get better at the breakdown. But that comes with disadvantages as well, they might give us more space to attack."
The All Blacks' pack, and in particular lock Brodie Retallick and skipper and No8 Kieran Read, who hasn't played for nearly two months due to his broken thumb, were outstanding, with Ioane, in his first test start, pretty good too.
"I guess we hold the advantage," Hansen said. "They're going to have to chuck everything at us to stay alive and we've got an opportunity to wrap it up."
Of Read's apparent soreness after the match, Hansen said: "That's not surprising. It was a test match. I didn't play and I was a bit sore just watching it."