Cardiff - Jari-Matti Latvala stretched his lead over Ford team-mate Petter Solberg to 24.5 seconds on the second day of the Wales Rally GB.
Latvala, who had a 12.1-second cushion after day one, won the closing asphalt superspecial stage on Saturday to home in on victory ahead of Sunday's final stages in the 10th rally of the world championship.
Sebastien Loeb of France remained in third place but was 30.9 seconds behind Latvala, meaning he was unlikely to earn a victory that will clinch his ninth straight world rally title.
Loeb was 54 points clear of Citroen team-mate Mikko Hirvonen in the overall standings with three more races left after Wales.
Results on Saturday after the second day of the Wales Rally GB:
1. Jari-Matti Latvala, Finland, Ford, 2 hour, 18 minutes, 05.3 seconds
2. Petter Solberg, Norway, Ford, 2:18:29.8
3. Sebastien Loeb, France, Citroen, 2:18:36.2
4. Mads Ostberg, Norway, Adapta, 2:18:55.2
5. Mikko Hirvonen, Finland, Citroen, 2:19:27.7
6. Ott Tanak, Estonia, Ford, 2:19:39.7
7. Evgeny Novikov, Russia, M-Sport Ford, 2:19:56.2
8. Thierry Neuville, Belgium, Citroen, 2:21:31.2
9. Matthew Wilson, Britain, Ford, 2:22:45.1
10. Martin Prokop, Czech Republic, Ford, 2:23:34.5