Mikko Hirvonen has stretched his lead over Sebastien Loeb to 10.9 seconds after an excellent performance on the second morning in Finland.
In slightly wet conditions, Hirvonen took three straight stage wins and now holds a more comfortable advantage approaching the rally's halfway point.
"The grip is very, very good," said the Ford driver. "For the boys behind maybe it's getting a litte bit softer and that might be slowing them down. But that's good."
Loeb (Citroen) said he was doing his utmost to keep Hirvonen in sight, but had no answer to his title rival's pace at home.
"I tried really hard, I took a lot of risks, but there's no change," Loeb admitted. "Mikko is too fast."
The lead pair's speed has taken them nearly a minute clear of their team-mates' Dani Sordo and Jari-Matti Latvala's battle for third. Despite suffering from food poisoning today, Latvala trimmed a little from Sordo's advantage and is confident he can claim the final podium place.
"It's been really,really hard, very demanding for me now," said Latvala. "But I'm satisfied, we've actually found a good rhythm. If we can keep this pace we can start to catch Sordo."
Sordo remained confident that he could hold the Ford off.
"Latvala is faster on the split times but I'm still happy," he said.
Matti Rantanen is now very secure in fifth for Munchi's Ford after problems for all his challengers this morning. Henning Solberg (Stobart Ford) passed the Finn on SS11, but then had to retire on the next stage with damaged suspension and a broken driveshaft.
Mads Ostberg (Adapta Subaru) has fallen away in sixth after a trip off the road and through a farmyard, while Jari Ketomaa punctured a tyre on the day's first stage and struggled with steering damage afterwards. He has fallen to eighth behind Sebastien Ogier (Citroen Junior).
Petter Solberg, who retired from second place yesterday morning after puncturing two tyres, rejoined under the superally system only to struggle with engine problems and then suspension damage today.
Kimi Raikkonen is still fourth among the Group N cars, having gained a place when Janne Tuohino retired, only to lose out to Patrik Flodin on the next stage as he encountered a few issues on his Abarth.
"The first stage was very bad for me," said Raikkonen. "It started to rain like crazy, we couldn't see and we had some difficulties. We've had some problems on the car and we had to switch some power off too. We'll get to service and see what we can do to fix it."
Leading positions after SS13:
Pos Driver Car Time/Gap
1. Mikko Hirvonen Ford 1h32m50.0s
2. Sebastien Loeb Citroen + 10.9s
3. Dani Sordo Citroen + 52.8s
4. Jari-Matti Latvala Ford + 1m01.1s
5. Matti Rantanen Ford + 2m32.9s
6. Mads Ostberg Subaru + 3m21.4s
7. Sebastien Ogier Citroen + 3m35.2s
8. Jari Ketomaa Subaru + 3m43.5s
9. Matthew Wilson Ford + 3m56.9s
10. Conrad Rautenbach Citroen + 6m06.6s