Thierry Neuville leads in Sardinia after Sebastien Ogier crashes out
Neuville, who has yet to win this season, ended the penultimate day 36.4 seconds ahead of Finnish teammate Esapekka Lappi (32), who had started Saturday leading eight-time world champion Ogier by a mere tenth of a second.
"It is a fine line between pushing hard and keeping the car on the road, and we were able to stay just on that line," said the leader.
He won three of the four morning stages and took the lead on the wet penultimate stage 14 when Ogier, who had been 18.2 seconds clear at one point in the afternoon, left the road and retired.
Lappi then slowed when he saw Ogier go off, with the rain coming down hard.
"It would have been very easy to go off as well. The aquaplaning was crazy at some points but thankfully we had no big moments," said the Finn.
World championship leader Kalle Rovanpera (22) was in third place for Toyota, but a minute and 50 seconds off the pace.
The rally is the sixth round of the season. Sunday features four stages, finishing with a Power stage with bonus points to be won.