Ford's Jari-Matti Latvala will go into the final day of the Rally of Sweden with a 23-second lead over fellow Finn and former team mate Mikko Hirvonen after extending his advantage on Saturday.
Latvala, who was 16.8 seconds clear of his Citroen rival at the start of the second leg, managed his tyres carefully on roads with thinning snow.
He now has just 84.84km between him and a second victory in the event, the second race of the world championship.
Norway's Petter Solberg, the former champion who is now Latvala's Ford team mate, was in third place and 51.4 seconds off the lead.
Solberg faced a tough battle with compatriot Mads Ostberg, 11.1 seconds behind in fourth spot for Ford.
Eight-times champion Sebastien Loeb, who won the Monte Carlo season-opener last month but ran into a snow bank on Friday, moved up to sixth place from seventh but was nearly three minutes behind Latvala.
There was more misery for Frenchman Loeb on Saturday when he spun early on and then suffered a puncture on the 17th stage, dropping him back temporarily.
"Anything is possible tomorrow but we didn't have a very good day," he told the world rally championship website (www.wrc.com).
Loeb shared victory on the final Hagfors sprint stage of the day with Estonian Ott Tanak.
There are six more stages on Sunday before the ceremonial finish in Karlstad.
Irishman Craig Breen, World Rally Championship Academy champion, looks on course to continue his fantastic start to the 2012 season.
The Ford Fiesta S2000 driver is firmly in place to take second in the category and 18 championship points.
There was some drama at the end of stage 16 when Breen reported a front differential problem but this was later clarified to be a broken front brake disc.
Breen said: “We shattered a front brake disc on stage 16 but managed to remove the disc and calliper on the road section to stage 17.
"The handling was then very difficult as when you press the brakes the car wants to jump out of the ruts and that’s the only place there’s any grip, so very tough in there, but we’re here and we can now make repairs in service.”