Kris Meeke will take a 13-second lead into the final day of the Rally Spain World Championship round.
The 38-year-old Dungannon man trailed leader Andreas Mikklesen by three seconds as he was in third spot after Friday's action but immediately took the lead on Saturday.
The Northern Irishman's win in stage seven gave him a nine-second advantage which he managed to extend slightly during Saturday's remaining stages.
Sebastien Ogier is second with Estonian Ott Tanak 14.5 seconds behind Meeke.
A dramatic victory in Mexico remains a rare Meeke highlight in 2017 with crashes in Monte Carlo, Sweden, Portugal, Argentina, Italy and Germany along with an engine failure while leading in Corsica, ruining his campaign.
Meeke's regular exits this season led to him being dropped for Rally Poland during the summer but the Northern Irishman will hope that a victory on Sunday can secure his retention of the Citroen drive for 2018.
The Mexico triumph was the fourth of his career after his 2015 win in Argentina and 2016 successes in Portugal and Finland.
He will have to negotiate six further stages on Sunday to clinch another WRC victory.