Leg 1: Friday
After winning Thursday’s curtain-raising speed test, the Estonian was briefly pegged back by Sébastien Ogier on Friday morning as he struggled with the balance of his Toyota Yaris.
He then won all five remaining low-grip stages on narrow service tracks that corkscrewed through the Mosel vineyards and smooth country lanes in Saarland to lead the Frenchman, driving a Ford Fiesta, by 12.3sec.
Ogier distanced championship leader Thierry Neuville by 15.1sec, the Belgian requiring a gearbox change at mid-leg service after an oil leak.
The trio pulled clear of a fierce battle involving Elfyn Evans, Dani Sordo and Toyota Gazoo team-mates Jari-Matti Latvala and Esapekka Lappi.
Lappi held the initiative initially before Evans leap-frogged the other three drivers to claim fourth in his Fiesta by 1.0sec from Latvala. Sordo was 3.9sec further back in his i20, a tenth ahead of Lappi.
Leg 2: Saturday
Tänak extended his lead to 43.7sec after an Ogier mistake ended their duel.
They traded seconds in the morning’s four tests over Baumholder’s dusty tank training roads and Saarland’s lanes, before Ogier hit a rock in the second pass through the marathon Panzerplatte military road stage.
He stopped to replace a damaged front wheel, conceding more than 1min 40sec. Tänak was left in a strong position to add to his victory in Finland the previous month, despite failing to win any of the day’s eight tests.
Sordo and Latvala were split by 0.8sec in a fierce fight for second. Sordo won three of the military road stages while Latvala had the edge on the country lanes. He won two tests.
Neuville’s team reinstalled the differential and gearbox that was replaced the previous day, but he never found a comfortable rhythm and ended 8.0sec behind Latvala.
Esapekka Lappi was fifth in another Yaris, 6.3sec further back. Andreas Mikkelsen was sixth after handling issues, ahead of a despondent Ogier.
Craig Breen slumped from sixth to 10th after a final stage crash and Elfyn Evans retired his Fiesta after sliding into a field.
Leg 3: Sunday
Tänak completed a 39.2sec victory and gained four bonus points in the Power Stage to close to within 36 points of championship leader Neuville.
Neuville inherited an unexpected second place when the fight for the runners-up position between Latvala and Sordo ended in disaster for both. Latvala retired with hydraulic problems while Sordo crashed into the vines and an engine water leak forced him out.
Lappi finished third while two stage victories promoted Ogier to fourth. Team-mate Teemu Suninen was fifth on his asphalt debut in a World Rally Car after leapfrogging Mikkelsen.