Portugal’s state betting firm suspended wagers on a first-division match between Rio Ave and Feirense after an unusually large amount of money was placed on the game, sparking suspicions of match-fixing.

It is the first time that betting on a first-division match in Portugal has been suspended and Jogos Santa Casa’s two rivals, BetClic and Bet.pt, also followed suit.

“The gaming department decided to suspend bets due to the atypical volume waged,” Jogos Santa Casa said in a statement late on Monday before minnows Feirense’s 2-1 home win.

Jogos Santa Casa did not provide further details but sports daily O Jogo said suspicions of possible match-fixing were raised after a Chinese national bet 100,000 euros ($108,000) that Feirense would win the match.

The bet was made in the northern city of Povoa de Varzim, the newspaper added.

“What happened today is a black moment for Portuguese football,” Rio Ave coach Luis Castro said after the match.

The suspension of bets “calls into question players, coaches and institutions”, he added.

Feirense are 13th in the 18-team Portuguese league, four places behind Rio Ave.