Berlin - Borussia Dortmund fans called 'foul' on away ticket prices for their team's German Cup quarter-final at Stuttgart by hurling dozens of yellow and red balls onto the pitch.
Dortmund fans took exception after Stuttgart raised ticket prices at the Mercedes Benz Arena for Tuesday night's game as Borussia booked their place in the last four with a 3-1 win over their hosts.
After boycotting the first 20 rows of the away section, Dortmund fans then threw the brightly-coloured balls onto the pitch midway through the first-half which Borussia players, led by captain Mats Hummels, had to pick up as the game was briefly halted.
"Football must be affordable!" read one banner in the away section as the cheapest ticket for Tuesday's match was 38.50 euros, plus booking fee, while the most expensive were more than €70 .
"We wanted to try and put a good face on the matter, but at the same time show that it was not on," said Marc Quambusch, the initiative's spokesman.
The fans carried out the protest with Dortmund's blessing.
"It's the case that VfB Stuttgart raised the prices for tickets by 25%, with prices around €70," said Dortmund's press officer Sascha Fligge in the pre-match press conference.
"The fans are very critical of this and we support them."
Stuttgart said they had put prices up for away fans after Dortmund had done exactly the same thing for a Bundesliga match between the clubs at Borussia's Signal Iduna Stadium.
Ticket prices are an issue in England's Premier League after 10,000 fans walked out of Liverpool's 2-2 draw at home to Sunderland last Saturday over the €77 it will cost for the most expensive match ticket at Anfield next season.
Prices remain reasonable in Germany's top flight where tickets range from €16.70 to €78.20 for a home Bundesliga match at Borussia Dortmund, while Bayern Munich charge from €15 up to €70 euros for home league games.