Politt attacked Australian Harry Sweeny (Lotto Soudal) and Imanol Erviti (Movistar) with just under 12 kilometres remaining in the race, soloing into the finish with his trademark hard-pedalling style and celebrating a rare victory.
“It’s my passion cycling," said Politt, "and for my whole family there’s so much time away from home with training camps and races. Now it’s the biggest win you can have winning a stage in the Tour. It’s unbelievable. It’s a dream to win a stage in the Tour de France."
Politt was aggressive all day to first form the break and then attack early with still 50 kilometres left to ride, all in the successful attempt to the make the race too hard for the other riders.
"Today at the start we had to decide that Peter (Sagan) was going to leave the race because of his knee problem and we had to change our plans," said Politt. "In the end it was a bit of a bigger group. There was quite a lot of sprinters in our group and I knew I had to make the race hard and attack quite early. I did the first attack and then we were just four guys.
“My sports director told me it was the last wave into the finish and to give it everything I had. I did it again and attacked, then the seconds were coming, 20 seconds, 30 seconds. To come in solo into the finish line, it’s unbelievable."
Sweeny had to settle for third after Erviti out-sprinted him for second.
A hard and fast start in windy conditions saw the race blown apart in the early kilometres, with echelons forming across the road as teams and riders tried to ensure that they were represented in the day's break. With so many riders recovering after the mountains and limited teams keen for the race to end in a sprint, it was a rare opportunity for the riders that specialise in flatland riding to win a Tour de France stage.
Australian Harry Sweeny (Lotto-Soudal), André Greipel (Israel Start-Up Nation), Edward Theuns (Trek-Segafredo), Julian Alaphilippe (Deceuninck-QuickStep), Imanol Erviti (Movistar), Nils Politt (BORA-hansgrohe), Stefan Küng (Groupama-FDJ), Stefan Bissegger (EF Education-Nippo), Connor Swift (Arkea-Samsic), Brent Van Moer (Lotto Soudal), Luka Mezgec (Team BikeExchange), Sergio Henao (Qhubeka-NextHash), Edvald Boasson Hagen (TotalEnergies) formed the eventual move that went clear.
The gap blew out from there, extending steadily all the way to the finish with the sprinters' teams uninterested and no general classification threats within the breakaway.
Nils Politt attacked his breakaway companions with just under 50 kilometres to race, kicking off the attempts to ditch their rivals and win the stage. That move was eventually subdued, with the attacks continuing to flow with the cooperation in the front group halted.
An attack while eating by Sweeny with 40 kilometres to go caught out the breakaway riders, with Küng, Politt and Erviti able to jump across and follow the Australian. The quartet worked well together to build up their advantage over the seven riders chasing and managed to get out to a half-minute lead.
A short, uncategorised climb with 14 kilometres to go saw Sweeny lead the attacks on steep ascent, dropping Küng as Politt and Erviti were able to respond.
With van Moer marking moves for Sweeny behind, the gap to the chasing seven grew to a minute lead with 12 kilometres to go, with the now trio the big favourites to hold on to contest the win. Sweeny's attack made him the watched man, and the cooperation of the front riders stalled a bit until Politt launched a big attack, mouth wide open sucking in oxygen as his attack initially went unanswered.
Sweeny and Erviti tried to work together to catch up with Politt, but the big German gradually was able to increase his advantage as he hammered towards the finish, averaging 57.2 kilometres from the point of his attack to the finish.
Politt crossed the line with some big demonstrative celebrations, taking only the second professional victory of his career, his previous win at the Deutschland Tour in 2018.
Sweeny led out the sprint for second, with Erviti just easing over the top of the Australian in the finish, 30 seconds behind the race winner.
The peloton finished almost 16 minutes later, with Mark Cavendish claiming three sprint points in the battle for green, with Michael Matthews (Team BikeExchange) claiming the remaining two available.
Tadej Pogačar (UAE Team Emirates) maintained the race lead comfortably on a day where there was little action from the peloton after the break was established.
The Tour de France will continue with Stage 13, a 220 kilometre stage from Nîmes to the medieval town of Carcassonne. Watch from 2030 AEST on SBS, SBS OnDemand, with the race coverage starting on the SKODA Tour Tracker from 1955 AEST.