Confirming polling which shows that the AfD have hugely increased their share of the vote since Germany decided to open its doors to refugees in late August 2015, the right-wing party won on average 13.2 percent of votes at local election in the central German state of Hesse on Sunday.
This result made the AfD the third largest party behind Chancellor Angela Merkel's Christian Democratic Union (CDU) and the Social Democratic Party (SPD), who won 28.2 percent and 28.0 percent respectively, Hessischer Rundfunk reports.
Both of Germany's largest political parties lost a substantial share of the vote from the last elections.
In Hesse's capital Wiesbaden, the AfD scored a particular success, winning 16.2 percent of the vote.
But it is the result in Frankfurt, a global financial centre with a cosmopolitan population, which in many ways came as a surprise.
Up until this point the AfD has largely won votes in economically marginalized areas such as the states of former East Germany.
The AfD's previous best election result was 12.2 percent of the vote in 2014 state elections in the eastern state of Brandenburg, one of the poorest regions in Germany.
In former West Germany, the AfD had previously struggled to make the 5 percent cut of votes necessary to make it into a state parliament, scoring a best of 6.1 percent in Hamburg in 2015.
While the AfD were born as a single issue party in 2013, fighting to dismantle the European single currency, they lurched to the right in the summer of 2015 when party members toppled founder and economics professor, Bernd Lucke.
In recent months the party's new leadership has caused outrage by suggesting that it is acceptable to shoot at immigrants who cross into Germany illegally.
With major state elections coming up in three German states in mid-March, the results also act as a shot across the bow of the CDU and SPD which both support an open-door refugee policy.
"It's terrifying," Eva Högl, vice chairwoman of SPD in the national parliament, told broadcaster ARD, saying the AfD are following an "unspeakable course”.
“If they enter the state parliaments with double digits and maybe even the federal parliament, this will change the whole German community in a very negative way.
“Elections are way too important to teach someone a lesson - it is about forming our society and democracy."
"The traditional parties are paying the price for the voters' protest,” Manfred Pentz, CDU secretary general of Hesse, told to the Süddeutsche Zeitung on Monday.
Neo-Nazi party win 17 percent in one district
The success of the AfD was not the only result to send shock waves through the political establishment.
The neo-Nazi NPD party managed to win 17 percent in Leun, making them the third largest party in the 6,000-inhabitant town.
They also won 14 percent of the vote in Büdingen, a town of 21,000 people which also has the largest refugee shelter in Hesse.
At the last local elections, the NPD only managed to win 2 percent of the vote in Büdingen. Statewide, though, the NPD scored a much less impressive 0.3 percent of the vote.
'Search for easy answers'
Benno Hafeneger, a professor at the Philipp University of Marburg who specializes in right-wing extremism, told The Local that the AfD's success was due to "a search for fast, easy answers".
"People are frightened by something they don't know a thing about and the traditional parties don't represent the voters anymore," he argued.
“Our studies show that we have about 10 to 15 percent of people who are right-wing extremists [in Germany] - sometimes even more. But until now this never showed up in any vote," Hafeneger said.
“What does surprise me is the dimension which can be seen in the election. About 5 to 10 percent is typically for protest voters - in local elections especially you normally don't see the protest voters.
"The biggest surprise of all is, in the places where the AfD did not compete, the voters chose the NPD instead - so it seems to be not about the party itself, it is more about setting a statement,” Hafeneger went on.
How long the AfD could thrive would be contingent on the success with which Germany handles the refugee crisis, the academic said, adding that at this stage no one can tell whether they can establish themselves as a real political force.
With reporting by Raphael Warnke