Ott Tanak of DMACK World Rally Team strengthened his grip on the Rally Poland with a clean sweep of stage victories on Saturday.
The Estonian increased his overnight lead over Andreas Mikkelsen (Volkswagen Motorsport II) from 4.2 seconds to 18 seconds, with New Zealander Hayden Paddon (Hyundai Motorsport) a further 6.9 seconds back in third.
Tanak, who is eighth in the overall World Rally Championship standings, was keen to retain focus as he seeks to secure his first victory of the season in Sunday's final stage.
"The surface on the previous stage was soft but this one was harder and our tyres worked well," he told WRC.com.
"It's far too early to think about Sunday afternoon's finish.
"These are proper stages and the speeds are high, so the concentration needs to be as high as possible."
Hyundai team-mates Thierry Neuville and Sebastien Ogier, meanwhile, struggled in the sandy conditions, with the Belgian breaking his gear lever as he battled to hold on to fourth place and French championship leader Ogier dropping down to sixth.
Finnish driver Jari-Matti Latvala (Volkswagen) overcame an engine stall and missing a junction to climb to fifth.