Championship leader Ott Tanak, for Toyota, slipped to sixth place and nearly two minutes off the pace while reigning world champion Sebastien Ogier was third in a Citroen and 44.8 seconds behind Neuville.
There are two stages remaining on Sunday, with the Bastia-based rally finishing with a Power Stage worth up to five additional points at Calvi.
Neuville won two of Saturday's stages and took the lead after the final one, a 47km long Castagniccia speed test.
"This morning, during the long stage particularly, we couldn’t really find the feeling we wanted, but things came good in the afternoon," said the Belgian.
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"When you have the right rhythm in the car, it’s possible to set fast times without taking risks. That’s exactly what we could do and we now need to defend our lead on Sunday."
Evans, the overnight leader on Friday, had been locked in a battle with Tanak for much of the day until the Estonian suffered a puncture and lost two minutes.
The Welshman had led into the final stage and was shocked to have lost so much time to Neuville.
"Four and a half seconds isn’t too much and we can fight for that tomorrow. We know that we have the pace to win this rally, and that’s what we’ll be focused on," said Evans.
Six-times world champion Ogier felt he could have won the final stage had he not lost power for a couple of kilometres towards the end, but was still pleased to be in the top three again ahead of another big battle on Sunday.
(Reporting by Alan Baldwin in London, editing by Ed Osmond)
