Ott Tanak leads the Rally of Portugal by 4.6 seconds after a number of drivers hit problems on a difficult opening day.
The Estonian M-Sport Ford driver took over the lead during the second stage of the afternoon and held on as the drama unfolded behind him.
Toyota's Jari-Matti Latvala was second at that stage but the Finn dropped to 13th, nearly five minutes off the lead, after rolling his Yaris at the start of special stage seven.
A puncture and then broken suspension on his Citroen C3, both on stage seven, forced Northern Ireland's Kris Meeke out of the race.
New Zealand's Hayden Paddon had been as high as third at one point but an electrical fault on his Hyundai eventually dropped him outside the top 20.
All of those problems meant Hyundai's Dani Sordo was able to finish the day second, the Spaniard beating reigning world champion Sebastien Ogier by just 0.4 seconds.
Frenchman Ogier currently leads the series points standings in his M-Sport Ford.