Berlin (AFP) – Just seven years after being founded, RB Leipzig, sponsored by energy drinks giants Red Bull, will play in the Bundesliga next season after their second division promotion was confirmed Sunday.

Goals by Sweden’s Emil Forsberg and Marcel Halstenberg sealed their 2-0 win at home to Karlsruhe, in front of 42,559 fans, which means they will join second division champions Freiburg in Germany’s top flight next season.

“Right now there is nothing better, it’s unbelievable,” said Leipzig’s ex-Germany defender Marvin Compper.

“We had to break down a lot of resistance, but at the end we deserve to go up.

“There are no other words for this.”

But RB Leipzig will not receive a warm welcome in the Bundesliga from many fans of Germany’s top clubs.

Rasenballsport Leipzig were founded in 2009 when Red Bull, owned by Austrian billionaire Dietrich Mateschitz, bought the licence from lower league side SSV Markranstaedt.

They changed their name, but German Football League (DFL) rules meant they were not allowed to copy the likes of Red Bull New York or Red Bull Salzburg in using the company name in the title.

After a year in Germany’s fifth division, the rise was constant: three years in the regional (fourth division), a year in the third tier and two in the second, before finally winning full Bundesliga status.

RB Leipzig will become the 55th club to play in the Bundesliga, and next season will be the first since 2008/09 when a club from the former East Germany will feature in the top flight.

They can expect a cold reception in the Bundesliga, especially against traditional clubs like Borussia Dortmund and Schalke.

Like Bayer Leverkusen, who are sponsored by pharmaceutical company Bayer, VW-backed Wolfsburg and Hoffenheim, who are bank-rolled by software magnate Dietmar Hopp, RB Leipzig are unpopular with fans due to their backing.

During RB’s rise through the leagues, opposition fans rioted during matches, organised protests and staged boycotts, while Leipzig’s players have been spat at.

After a long search, Ingolstadt’s Ralph Hasenhuettl was appointed as Leipzig coach for next season, while Ralf Rangnick will be director of football after coaching the side this term.

Hasenhuettl was booed by his club’s own fans in his final home match against Bayern Munich on Saturday and later broke down in tears in the post-match press conference.

“You’d rather be Rangnick’s jester than king of the Schanzer? (Ingolstadt’s nickname)”, questioned one banner at Ingolstadt’s Audi-Sportpark stadium.

The current Leipzig squad includes Rani Khedira, brother of Germany midfielder Sami Khedira, Compper, who won his single cap for Germany in 2008, and USA international striker Terrence Boyd, but bigger names are sure to be signed before next season.

The only downside to Leipzig’s promotion celebrations at their Red Bull Arena stadium on Sunday was written all over Rangnick’s grimacing face.

The RB boss suffered a suspected torn hamstring after slipping while being chased by players who were successful in their attempts to pour beer over him.