Jari-Matti Latvala charged into the Rally GB lead as the event completed its penultimate day.
Having trailed Sebastien Loeb at lunchtime, Latvala won all three stages this afternoon to put his Ford 6.1 seconds ahead of the Citroen going into the final leg.
Loeb denied that he was backing off now the championship was secure, and said he was doing his utmost to beat Latvala.
"I cannot do anything," said Loeb at the end of leg-closer Myherin. "Maybe he's much better than me or maybe we are cleaning a bit, I don't know.
"I did a perfect stage. If you watch it on the video, you'll see no mistakes anywhere."
Latvala was delighted with his pace on the last loop and rued having not been so quick earlier on.
"It's been gong really well, like yesterday afternoon," said the Finn. "So now tomorrow morning I need to wake up and have a very, very clear head.
"I have got good confidence, and I'm so hungry for the victory.
"He's now eight times world champion, maybe he hasn't got that spark anymore to fight 100 per cent completely [for the rally win], but I have."
Mads Ostberg remains a lonely third, but is having to nurse his Stobart Ford due to an engine issue. The team has advised him to keep the revs high to combat the problem, and he is optimistic of getting back to service for attention.
After his morning engine issues, Kris Meeke had a healthy Mini again this afternoon and moved past Matthew Wilson before closing the gap to Wilson's Stobart team-mate Henning Solberg in fourth.
Evgeny Novikov showed better form this afternoon to move within sight of fellow Ford men Dennis Kuipers and Ott Tanak in seventh and eighth, with Tanak struggling with some technical issues on this loop.
Craig Breen clinched the inaugural WRC Academy title in an ultra-close showdown with rival Egon Kaur, which came down to the bonus points for fastest stage times as Breen overcame a 20-point deficit to Kaur this weekend.
Leading positions after SS17: Pos Driver Team/Car Time/Gap 1. Jari-Matti Latvala Ford 2h38m37.9s 2. Sebastien Loeb Citroen + 6.1s 3. Mads Ostberg Stobart Ford + 2m43.9s 4. Henning Solberg Stobart Ford + 5m35.0s 5. Kris Meeke Mini + 6m20.0s 6. Matthew Wilson Stobart Ford + 7m05.6s 7. Dennis Kuipers FERM Ford + 7m57.4s 8. Ott Tanak M-Sport Ford + 8m02.3s 9. Evgeny Novikov Abu Dhabi Ford + 8m22.3s 10. Ken Block Monster Ford + 13m24.7s