Tänak, who won the previous rounds in Finland, Germany and Turkey, ended a tough day in the north Wales forests with a 28.8sec lead in his Toyota Yaris over series leader Thierry Neuville.
He reeled off a hat-trick of speed test wins this morning, building a near-10sec cushion that allowed for caution in the next two foggy and rain-soaked tests. He won two more this afternoon when the first three stages were repeated.
Frequent surface changes and inconsistent grip in the constantly changing conditions left drivers struggling for confidence on the predominantly gravel roads, but improved afternoon weather played into Tänak’s hands.
“It was a really good day,” said the Estonian, whose recent form has propelled him into a three-way title fight with Neuville and five-time champion Sébastien Ogier. “It looks like we’ve made a good step with the car and in the really low-grip conditions we were competitive.”
Local hero Elfyn Evans scored his maiden win here 12 months ago and was Tänak’s closest challenger until an engine misfire stopped his Ford Fiesta en route to the afternoon stages.
Neuville capitalised to take second after a frustrating start in his Hyundai i20. The Belgian’s car would not handle as he wished and he overshot a junction and hit a chicane before set-up changes did the trick and he climbed from fifth.
He headed a quartet of drivers covered by less than 10sec. Jari-Matti Latvala briefly held second in another Yaris, but ended 2.5sec behind Neuville after losing his rhythm in this afternoon’s long Brenig stage.
Esapekka Lappi recovered from an early spin to make it three Yaris cars in the top four. The Finn was 4.6sec adrift of his fellow countryman and 2.3sec clear of Ogier’s Fiesta.
Ogier was third until first and second gears broke which, combined with two spins, relegated him to eighth before a late recovery. Craig Breen completed the top six in a Citroën C3.
Drivers face more than 15 hours at the wheel on Saturday when they journey south to mid-Wales. After a 05.30 start, they tackle five stages, the first four of which are repeated in the afternoon. It adds up to 150.24km of action with no opportunity for service during the day.